Every triangle has three sides. The sides allow us to classify the different types of triangles according to their size.
For example, a triangle with two equal sides (edges) is an isosceles triangle and one in which all its sides (edges) are equal is an equilateral triangle. While a triangle that has all its sides different is an equilateral triangle.
Can a triangle have two right angles?
Look at the two triangles below. Is EC a side of one of the triangles?
Which of the following is the height in triangle ABC?
ABC is an isosceles triangle.
AD is the median.
What is the size of angle \( ∢\text{ADC} \)?
Given the following triangle:
Write down the height of the triangle ABC.
Can a triangle have two right angles?
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.
No
Look at the two triangles below. Is EC a side of one of the triangles?
Every triangle has 3 sides, let's go over the triangle on the left side:
Its sides are: AB, BC, CA
This means that in this triangle, side EC does not exist.
Let's go over the triangle on the right side:
Its sides are: ED, EF, FD
This means that in this triangle, side EC does not exist.
Therefore, EC is not a side in either of the triangles.
No.
Which of the following is the height in triangle ABC?
Let's remember the definition of height of a triangle:
A height is a straight line that descends from the vertex of a triangle and forms a 90-degree angle with the opposite side.
The sides that form a 90-degree angle are sides AB and BC. Therefore, the height is AB.
AB
ABC is an isosceles triangle.
AD is the median.
What is the size of angle ?
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.
90
Given the following triangle:
Write down the height of the triangle ABC.
An altitude in a triangle is the segment that connects the vertex and the opposite side, in such a way that the segment forms a 90-degree angle with the side.
If we look at the image it is clear that the above theorem is true for the line AE. AE not only connects the A vertex with the opposite side. It also crosses BC forming a 90-degree angle. Undoubtedly making AE the altitude.
AE
Find the measure of the angle \( \alpha \)
Tree angles have the sizes 56°, 89°, and 17°.
Is it possible that these angles are in a triangle?
Tree angles have the sizes:
90°, 60°, and 30.
Is it possible that these angles are in a triangle?
Tree angles have the sizes:
50°, 41°, and 81.
Is it possible that these angles are in a triangle?
Tree angles have the sizes:
69°, 93°, and 81.
Is it possible that these angles are in a triangle?
Find the measure of the angle
It is known that the sum of angles in a triangle is 180 degrees.
Since we are given two angles, we can calculate
We should note that the sum of the two given angles is greater than 180 degrees.
Therefore, there is no solution possible.
There is no possibility of resolving
Tree angles have the sizes 56°, 89°, and 17°.
Is it possible that these angles are in a triangle?
Let's calculate the sum of the angles to see what total we get in this triangle:
The sum of angles in a triangle is 180 degrees, so this sum is not possible.
Impossible.
Tree angles have the sizes:
90°, 60°, and 30.
Is it possible that these angles are in a triangle?
Let's remember that the sum of angles in a triangle is equal to 180 degrees.
We'll add the three angles to see if their sum equals 180:
Therefore, these could be the values of angles in some triangle.
No.
Tree angles have the sizes:
50°, 41°, and 81.
Is it possible that these angles are in a triangle?
Let's remember that the sum of angles in a triangle is equal to 180 degrees.
We'll add the three angles to see if their sum equals 180:
Therefore, these cannot be the values of angles in any triangle.
Impossible.
Tree angles have the sizes:
69°, 93°, and 81.
Is it possible that these angles are in a triangle?
Let's remember that the sum of angles in a triangle is equal to 180 degrees.
We'll add the three angles to see if their sum equals 180:
Therefore, these cannot be the values of angles in any triangle.
No.
Tree angles have the sizes:
76°, 52°, and 52°.
Is it possible that these angles are in a triangle?
Tree angles have the sizes:
31°, 122°, and 85.
Is it possible that these angles are in a triangle?
Tree angles have the sizes 94°, 36.5°, and 49.5. Is it possible that these angles are in a triangle?
Three angles measure as follows: 60°, 50°, and 70°.
Is it possible that these are angles in a triangle?
Tree angles have the sizes:
90°, 60°, and 40.
Is it possible that these angles are in a triangle?
Tree angles have the sizes:
76°, 52°, and 52°.
Is it possible that these angles are in a triangle?
Let's remember that the sum of angles in a triangle is equal to 180 degrees.
We will add the three angles to find out if their sum equals 180:
Therefore, these could be the values of angles in some triangle.
Yes.
Tree angles have the sizes:
31°, 122°, and 85.
Is it possible that these angles are in a triangle?
Let's remember that the sum of angles in a triangle is equal to 180 degrees.
We'll add the three angles to see if their sum equals 180:
Therefore, these cannot be the values of angles in any triangle.
Impossible.
Tree angles have the sizes 94°, 36.5°, and 49.5. Is it possible that these angles are in a triangle?
Let's remember that the sum of angles in a triangle is equal to 180 degrees.
We'll add the three angles to see if their sum equals 180:
Therefore, these could be the values of angles in some triangle.
Possible.
Three angles measure as follows: 60°, 50°, and 70°.
Is it possible that these are angles in a triangle?
Recall that the sum of angles in a triangle equals 180 degrees.
Let's add the three angles to see if their sum equals 180:
Therefore, it is possible that these are the values of angles in some triangle.
Possible.
Tree angles have the sizes:
90°, 60°, and 40.
Is it possible that these angles are in a triangle?
Let's remember that the sum of angles in a triangle is equal to 180 degrees.
We'll add the three angles to see if their sum equals 180:
Therefore, these cannot be the values of angles in any triangle.
Yes.