Geometry - Triangle Angle Theorems & Isosceles Triangles

Front

What is the sum of the interior angles of a triangle?

Back

The sum of the interior angles of a triangle is always 180 degrees.

Front

What is an isosceles triangle?

Back

An isosceles triangle is a triangle that has at least two sides of equal length.

Front

If two angles of a triangle are equal, what type of triangle is it?

Back

It is an isosceles triangle.

Front

What is the vertex angle of an isosceles triangle if each base angle measures 54 degrees?

Back

The vertex angle measures 72 degrees.

Front

How do you find the measure of an unknown angle in a triangle?

Back

You can find the measure of an unknown angle by subtracting the sum of the known angles from 180 degrees.

Front

What is the relationship between the angles in a triangle?

Back

The sum of the angles in a triangle is always 180 degrees.

Front

What is the base of an isosceles triangle?

Back

The base of an isosceles triangle is the side that is not equal in length to the other two sides.

Front

If one angle of a triangle measures 90 degrees, what type of triangle is it?

Back

It is a right triangle.

Front

What is the formula for the exterior angle of a triangle?

Back

The exterior angle is equal to the sum of the two opposite interior angles.

Front

In triangle ABC, if angle A = 35 degrees and angle B = 65 degrees, what is angle C?

Back

Angle C = 180 - (35 + 65) = 80 degrees.