Parts of a Triangle Practice Problems & Worksheets

Master triangle terminology with interactive practice on heights, medians, angle bisectors, and perpendicular bisectors. Build geometry skills step-by-step.

📚What You'll Master in Triangle Parts Practice
  • Identify and draw triangle heights from vertices to opposite sides
  • Locate medians that divide triangle sides into equal segments
  • Construct angle bisectors that create equal angles at vertices
  • Draw perpendicular bisectors from midpoints of triangle sides
  • Find midsegments connecting midpoints of two triangle sides
  • Distinguish between different types of triangle lines and their properties

Understanding Parts of a Triangle

Complete explanation with examples

Terms used in triangle calculations

  • Line

A line is a general term for straight lines (hence its name) that extend from a specific point on the triangle.

  • Height

Height is a line that extends from a specific vertex and reaches perpendicularly to the opposite side, creating a right angle. The height is marked with the letter h (from the word height).

  • Median

The median is also a line extending from a specific vertex to the opposite side, but it reaches exactly the middle of the opposite side and divides it into two equal parts.

  • Angle Bisector

An angle bisector is a line that extends from a specific vertex and actually divides the vertex into two equal angles.

  • Perpendicular Bisector

A perpendicular bisector is a line that extends from the middle of a side perpendicular to it.

  • Midsegment

A midsegment is a line that connects the midpoints of two sides and is parallel to the third side, with its length being half of it.

  • Opposite Side

An opposite side is the side that is located opposite to a specific vertex and does not pass through it.

Diagram of a triangle ABC illustrating key geometric concepts: height (H) in green, median in blue, angle bisector in red, perpendicular bisector from CB in orange, midsegment in purple, and the side opposite to vertex A highlighted in orange. Labels are color-coded for clarity.

Detailed explanation

Practice Parts of a Triangle

Test your knowledge with 36 quizzes

Determine the type of angle given.

Examples with solutions for Parts of a Triangle

Step-by-step solutions included
Exercise #1

ABC is an isosceles triangle.

AD is the median.

What is the size of angle ADC ∢\text{ADC} ?

AAABBBCCCDDD

Step-by-Step Solution

In an isosceles triangle, the median to the base is also the height to the base.

That is, side AD forms a 90° angle with side BC.

That is, two right triangles are created.

Therefore, angle ADC is equal to 90 degrees.

Answer:

90

Video Solution
Exercise #2

ABC is a triangle.

What is the median of the triangle?

AAABBBCCCEEEFFFDDD

Step-by-Step Solution

To solve the problem of identifying the median of triangle ABC \triangle ABC , we follow these steps:

  • Step 1: Understand the Definition - A median of a triangle is a line segment that extends from a vertex to the midpoint of the opposite side.
  • Step 2: Identify Potential Medians - Examine segments from each vertex to the opposite side. The diagram labels these connections.
  • Step 3: Confirm the Median - Specifically check the segment EC in the context of the line segment from vertex E E to the side AC AC , and verify it reaches the midpoint of side AC AC .
  • Step 4: Verify Against Options - Given choices allow us to consider which point-to-point connection adheres to our criterion for a median. EC is given as one of the choices.

Observation shows: From point E E (assumed from the label and position) that line extends directly to point C C —a crucial diagonal opposite from considered midpoint indications, suggesting it cuts AC AC evenly, classifying it as a median.

Upon reviewing the given choices, we see that segment EC EC is listed. Confirming that EC EC indeed meets at C C , the midpoint of AC AC , validates that it is a true median.

Therefore, the correct median of ABC \triangle ABC is the segment EC EC .

Answer:

EC

Exercise #3

AB is a side in triangle ADB

AAABBBCCCDDDEEE

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

Video Solution
Exercise #4

According to figure BC=CB?

AAABBBCCCDDDEEE

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

Video Solution
Exercise #5

AD is the median in triangle ABC.

BD = 4

Find the length of DC.

AAABBBCCCDDD4

Step-by-Step Solution

To solve this problem, since AD AD is a median of triangle ABC ABC , the median divides the opposite side BC BC into two equal segments.

Given BD=4 BD = 4 , this means that DC DC must also be equal to 4.

Therefore, the length of DC DC is 4 4 .

Answer:

4

Video Solution

Frequently Asked Questions

What is the difference between a height and a median in a triangle?

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A height (altitude) is a line from a vertex perpendicular to the opposite side, forming a 90° angle. A median is a line from a vertex to the midpoint of the opposite side, dividing that side into two equal parts. The height focuses on perpendicularity, while the median focuses on bisecting the opposite side.

How do you identify the opposite side of a triangle vertex?

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The opposite side is the side that doesn't touch the vertex you're looking at. For example, in triangle ABC, the opposite side to vertex A is side BC. The opposite side is always across from the vertex, never connected to it.

What makes an angle bisector different from other triangle lines?

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An angle bisector divides an angle at a vertex into two equal smaller angles. Unlike heights or medians that go to the opposite side, angle bisectors focus on splitting the angle itself. If angle A is 60°, its angle bisector creates two 30° angles.

How long is a midsegment compared to the third side of a triangle?

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A midsegment is always exactly half the length of the third side (the side it's parallel to). This is the Triangle Midsegment Theorem. For example, if the third side is 10 units long, the midsegment will be 5 units long.

Where does a perpendicular bisector start in a triangle?

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A perpendicular bisector starts from the midpoint of any triangle side and extends perpendicular (at 90°) to that side. It doesn't originate from a vertex like heights, medians, or angle bisectors do. Instead, it bisects the side itself.

Can a triangle have multiple heights, medians, and angle bisectors?

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Yes! Every triangle has exactly three of each: three heights (one from each vertex), three medians (one from each vertex), and three angle bisectors (one for each angle). Each serves a different geometric purpose in triangle analysis.

What tools do I need to draw triangle parts accurately?

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You'll need: 1) A ruler for measuring and drawing straight lines, 2) A protractor for measuring angles and creating perpendicular lines, 3) A compass for finding midpoints and creating equal segments. These tools help ensure your triangle constructions are precise.

Why are triangle parts important in geometry problems?

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Triangle parts help solve area calculations, prove congruence, find missing measurements, and understand triangle properties. Heights are used in area formulas, medians help locate centroids, and angle bisectors are crucial for angle relationships and triangle similarity problems.

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