Examples with solutions for Parts of a Triangle: Identifying and defining elements

Exercise #1

Is the straight line in the figure the height of the triangle?

Video Solution

Step-by-Step Solution

The task is to determine whether the line shown in the diagram serves as the height of the triangle. For a line to be considered the height (or altitude) of a triangle, it needs to be a perpendicular segment from a vertex to the line that contains the opposite side, often referred to as the base.

Let's analyze the diagram:

  • The triangle is described by its vertices, forming a shape, and one side is the base. There's a line drawn from one vertex directed toward the opposite side.
  • To be the height, this line must be perpendicular to the side it meets (the base).
  • Though the figure does not explicitly show perpendicularity with a right angle mark, the line appears as a straight, direct connection from the vertex to the base. This is typically indicative of it being a height.
  • Assuming typical geometric conventions and the common depiction of heights in diagrams, the line shows properties consistent with being perpendicular to the opposite side, thereby functioning as the height.

Based on the analysis, the line is indeed the height of the triangle. Thus, the answer is Yes.

Therefore, the solution to the problem is Yes.

Answer

Yes

Exercise #2

In an isosceles triangle, the angle between ? and ? is the "base angle".

Step-by-Step Solution

An isosceles triangle is one that has at least two sides of equal length. The angles opposite these two sides are known as the "base angles."
The side that is not equal to the other two is referred to as the "base" of the triangle. Thus, the "base angles" are the angles between each of the sides that are equal in length and the base.
Therefore, when we specify the angle in terms of its location or position, it is the angle between a "side" and the "base." This leads to the conclusion that the angle between the side and the base is the "base angle."

Therefore, the correct choice is Side, base.

Answer

Side, base.

Exercise #3

Is the straight line in the figure the height of the triangle?

Video Solution

Step-by-Step Solution

To solve this problem, we must determine whether the dashed line in the presented triangle fulfills the criteria of being a height. Let's verify each critical aspect:

  • First, identify what a height (altitude) is: It is a line drawn from a vertex perpendicular to the opposite side.
  • Next, observe the figure. We have a triangle with a dash line drawn from the top vertex to a side that seems to extend from one corner of the base to another point on the extended base.
  • Since this line is not shown to be perpendicular to the base of the triangle (no right angle box), we cannot affirm that it fulfills our requirement.

As a result, the straight line does not meet the standard definition of a height for this triangle since it does not form the necessary 90-degree angle with the base. Therefore, as the line is not perpendicular to the opposite side, it is not the height.

Thus, the correct answer to the problem is No.

Answer

No

Exercise #4

Look at the two triangles below.

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Is AD a side of one of the triangles?

Step-by-Step Solution

The task is to determine if the segment AD AD is a side of any of the given triangles. Based on the diagram, we have two distinct triangles:

  • ABC\triangle ABC: Formed by the points A,B,C A, B, C .
  • DEF\triangle DEF: Formed by the points D,E,F D, E, F .

For ABC\triangle ABC, the sides are AB,BC, AB, BC, and CA CA .

For DEF\triangle DEF, the sides are DE,EF, DE, EF, and FD FD .

In analyzing both triangles, we observe that:

  • The side AD AD is not listed as one of the sides of either triangle.

Thus, the conclusion is clear: AD is not a side of either triangle.

Therefore, the answer is No.

Answer

No

Exercise #5

Look at the two triangles below. Is DE a side of one of the triangles?

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Step-by-Step Solution

To solve whether the segment DE DE is a side of one of the triangles, we must identify the sides of each triangle in the given diagram.

The first triangle is labeled ABC \triangle ABC :

  • Vertices are A,B, A, B, and C C .
  • Sides by this configuration are AB,BC, AB, BC, and AC AC .

The second triangle is labeled DEF \triangle DEF :

  • Vertices are D,E, D, E, and F F .
  • Sides formed are DE,EF, DE, EF, and DF DF .

Upon inspection, we see that DE DE is listed as a side of DEF \triangle DEF , confirming that it indeed is one side of this triangle.

Therefore, the conclusion is:

Yes, DE DE is a side of one of the triangles.

Answer

Yes

Exercise #6

In an isosceles triangle, the third side is called?

Step-by-Step Solution

To solve this problem, we need to understand what an isosceles triangle is and how its sides are labeled:

  • In an isosceles triangle, there are two sides that have equal lengths. These are typically called the "legs" of the triangle.
  • The third side, which is not necessarily of equal length to the other two sides, is known as the "base."

In terms of the problem, we want to determine the term used for the third side, which is the side that is not one of the two equal sides.

The correct term for the third side in an isosceles triangle is the "base." This is because the third side serves as a different function compared to the equal sides, which usually form the symmetrical parts of the triangle.

Among the given answer choices, choosing "Base" correctly identifies the third side of an isosceles triangle.

Therefore, the third side in an isosceles triangle is called the base.

Final Solution: Base

Answer

Base

Exercise #7

Fill in the blanks:

In an isosceles triangle, the angle between two ___ is called the "___ angle".

Step-by-Step Solution

In order to solve this problem, we need to understand the basic properties of an isosceles triangle.

An isosceles triangle has two sides that are equal in length, often referred to as the "legs" of the triangle. The angle formed between these two equal sides, which are sometimes referred to as the "sides", is called the "vertex angle" or sometimes more colloquially as the "main angle".

When considering the vocabulary of the given multiple-choice answers, choice 2: sides,mainsides, main accurately fills the blanks, as the angle formed between the two equal sides can indeed be referred to as the "main angle".

Therefore, the correct answer to the problem is: sides,mainsides, main.

Answer

sides, main

Exercise #8

According to figure BC=CB?

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Video Solution

Step-by-Step Solution

In geometry, the distance or length of a line segment between two points is the same, regardless of the direction in which it is measured. Consequently, the segments denoted by BC BC and CB CB refer to the same segment, both indicating the distance between points B and C.

Hence, the statement "BC = CB" is indeed True.

Answer

True

Exercise #9

Can a triangle have a right angle?

Video Solution

Step-by-Step Solution

To determine if a triangle can have a right angle, consider the following explanation:

  • Definition of a Right Angle: An angle is classified as a right angle if it measures exactly 9090^\circ.
  • Definition of a Right Triangle: A right triangle is a type of triangle that contains exactly one right angle.
  • According to the definition, a right triangle specifically includes a right angle. This is a well-established classification of triangles in geometry.

Thus, a triangle can indeed have a right angle and is referred to as a right triangle.

Therefore, the solution to the problem is Yes.

Answer

Yes

Exercise #10

AB is a side in triangle ADB

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Video Solution

Step-by-Step Solution

The problem asks us to confirm if AB is a side of triangle ADB.

Triangle ADB is defined by its vertices, A, D, and B. A triangle is formed when three vertices are connected by three sides.

  • Identify vertices: The vertices of the triangle are A, D, and B.
  • Identify sides: The triangle's sides should be AB, BD, and DA.
  • Observe: From the provided diagram, AB connects vertices A and B.

Therefore, based on the definition of a triangle and observing the connection between components, side AB indeed is a part of triangle ADB.

This confirms that the statement is True.

Answer

True

Exercise #11

DB is a side in triangle ABC

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Video Solution

Step-by-Step Solution

Let us determine whether DB DB is a side of triangle ABC ABC . This verification depends greatly on understanding the arrangement and positioning of the points given within the triangle.

From the diagram, points A A , B B , and C C form a triangle because they create a closed figure with three lines connecting one another, typical of triangle sides. On examining point D D and the line DB DB , we notice that D D seems to be an internal point, potentially serving roles like that of a median or an angle bisector, but not forming an external side of triangle ABC ABC .

Based on this understanding, line DB DB fails to fulfil the requirement of connecting two of the vertices of the triangle directly. Hence, it's internal and is not counted as an external side of triangle ABC ABC .

The conclusion based on the given options from the prompt: DB DB is not a side of triangle ABC ABC .

Answer

Not true

Exercise #12

Is the straight line in the figure the height of the triangle?

Video Solution

Step-by-Step Solution

To determine if the straight line in the figure is the height of the triangle, we must verify the following:

  • The line segment must extend from a vertex of the triangle and be perpendicular to the opposite side (or its extension).

In examining the figure provided, we notice that the triangle is formed by vertices at points A,B, A, B, and C C . Let's assume the base is the line segment BC \overline{BC} .

The line in question extends from a vertex A A and appears to intersect the base BC BC at a right angle.

  • Since it is extending from vertex to the opposite side and forming a right angle with it, this line meets the definition of an altitude.

Therefore, the line in the figure is indeed the height of the triangle. By confirming the perpendicular relationship, we determine that this geometric feature correctly describes an altitude.

Yes, the straight line in the figure is the height of the triangle.

Answer

Yes

Exercise #13

Is DE a side in the triangle BDC?

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Video Solution

Step-by-Step Solution

To solve this problem, we must analyze the provided geometric diagram carefully. The goal is to determine if line segment DE is a side of triangle BDC.

Let's examine the elements in the diagram:

  • Triangle BDC is outlined with vertices B, D, and C.
  • There is a line connecting points D and E, which does not coincide with the triangle's perimeter as sides are supposed to.
  • A clear check shows us that sides BDC are formed by line segments BD, DC, and CB in the triangle.
  • The line DE appears as an extension inside or outside of the triangle, making a clear indication that it is not part of the triangle itself.

Given the definition of a triangle's sides enclosed by its three vertices and the connectivity presented, it is apparent that DE is not recognized as one of the edges or sides that enclose triangle BDC.

Hence, the conclusion is: The statement "DE is a side in the triangle BDC" is Not true.

Answer

Not true

Exercise #14

Can a triangle have two right angles?

Video Solution

Step-by-Step Solution

The sum of angles in a triangle is 180 degrees. Since two angles of 90 degrees equal 180, a triangle can never have two right angles.

Answer

No

Exercise #15

Is the straight line in the figure the height of the triangle?

Video Solution

Step-by-Step Solution

In the given problem, we have a triangle depicted with a specific line drawn inside it. The question asks if this line represents the height of the triangle. To resolve this question, we need to discern whether the line is perpendicular to one of the sides of the triangle when extended, as only a line that is perpendicular from a vertex to its opposite side can be considered the height.

The line in question is shown intersecting one of the sides within the triangle but does not form a perpendicular angle with any side shown or the ground (as is required for it to be the height of the triangle). A proper height would typically intersect perpendicularly either at or along the extended line of the opposite side from a vertex.

Therefore, based on the visual clues provided and the typical geometric definition of a height (or altitude) in a triangle, this specific line does not fit the criteria for being a height.

Thus, we conclude that the line depicted is not the height of the triangle. The correct answer is No.

Answer

No

Exercise #16

Is the straight line in the figure the height of the triangle?

Video Solution

Step-by-Step Solution

To determine whether the given line is the height of the triangle, we start by understanding what defines the height of a triangle. The height, or altitude, is a line segment drawn from a vertex perpendicular to the opposite side (the base), forming a right angle with that side.
We need to examine whether the specified line in the diagram is indeed perpendicular to the base of the triangle. If the line is not perpendicular, then it cannot be considered the height.

Upon examining the triangle in the SVG diagram, observe the following:

  • The triangle, represented by vertices and sides, has a particular orientation.
  • The line in question is drawn from one vertex to another interior point or appears in the interior of the triangle.
  • Perpendicularity, if not explicitly shown by a right-angle marker, can also be evaluated by look or guided by other geometrical cues.
  • In this case, the line does not appear to be perpendicular to any side explicitly. Usually, height serves as intersection at 90 degrees.

Since the line does not form a 90-degree angle with the triangle's base as determined upon inspection, it is not the height. Therefore, the correct conclusion is that the line shown is not the height of the triangle.

Therefore, the correct answer is: No.

Answer

No

Exercise #17

Is the straight line in the figure the height of the triangle?

Video Solution

Step-by-Step Solution

To determine if the given straight line is the height of the triangle, we need to check whether it is perpendicular to the side it intersects (or its extension), which is the definition of a height (altitude) in a triangle.

Looking at the figure, the straight line is drawn from a vertex of the triangle to a point on the opposite side, but it is not perpendicular to that side or its extension. Therefore, the line does not meet the criteria for being a height of the triangle.

In conclusion, the line is not the height of the triangle because it is not perpendicular to the opposite side.

Therefore, the correct answer to the problem is No.

Answer

No

Exercise #18

Is the straight line in the figure the height of the triangle?

Video Solution

Step-by-Step Solution

To determine if the straight line in the figure is the height of the triangle, we need to ensure it is a line that starts from a vertex of the triangle and is perpendicular to the opposite side, known as the base. In the context of geometry, this line is called an altitude.

According to the given figure, the straight line appears to stem from one vertex of the triangle and intersect the base at a right angle, as indicated by a small square or a perpendicular marker at their intersection.

Since the line in question meets the definition of an altitude (perpendicular from a vertex to the opposite side), it indeed represents the height of the triangle relative to that specific base.

Hence, the answer to the problem is Yes.

Answer

Yes

Exercise #19

Is the straight line in the figure the height of the triangle?

Video Solution

Step-by-Step Solution

To determine if the straight line in the figure is the height of the triangle, we must verify whether it is perpendicular to the base of that triangle.

The height (or altitude) of a triangle is defined as a line segment from a vertex perpendicular to the line containing the opposite side (often referred to as the base).

Upon examining the figure, we see a triangle and a straight line drawn from one vertex towards the opposite side. However, there is no indication or mark suggesting that this line is perpendicular to the base.

Without explicit evidence of perpendicularity, such as a right-angle marking, we cannot assume that the line is the height of the triangle.

Thus, based on the geometric principles related to altitudes in triangles, we conclude the solution to the problem:

No, the straight line in the figure is not the height of the triangle.

Answer

No

Exercise #20

Is the straight line in the figure the height of the triangle?

Video Solution

Step-by-Step Solution

To determine if the straight line is the height of the triangle, we'll analyze its role within the triangle:

  • Step 1: Observe the triangle and the given line. The triangle seems to be made of three sides and a vertical line within it.
  • Step 2: Recall that the height of a triangle, in geometry, is defined as a perpendicular dropped from a vertex to the opposite side.
  • Step 3: Examine the positioning of the line: The vertical line starts at one vertex of the triangle and intersects the base, appearing to be perpendicular.
  • Step 4: Verify perpendicularity: Given that the line is shown as a clear vertical (and a small perpendicular indicator suggests perpendicularity), we accept this line as the height.
  • Step 5: Conclude with verification that the line is effectively meeting the definition of height for the triangle in the diagram.

Therefore, the vertical line in the figure is indeed the height of the triangle.

Yes

Answer

Yes