Interior Angles of 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

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

Back

It is a right triangle.

Front

What is an acute angle?

Back

An acute angle is an angle that measures less than 90 degrees.

Front

What is an obtuse angle?

Back

An obtuse angle is an angle that measures more than 90 degrees but less than 180 degrees.

Front

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

Back

Subtract the sum of the known angles from 180 degrees.

Front

If two angles of a triangle are 45 degrees each, what is the measure of the third angle?

Back

The third angle measures 90 degrees.

Front

What is the relationship between the angles in an isosceles triangle?

Back

In an isosceles triangle, the angles opposite the equal sides are equal.

Front

What is the formula to calculate the measure of an exterior angle of a triangle?

Back

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

Front

If the angles of a triangle are in the ratio 2:3:4, what are the measures of the angles?

Back

The angles measure 40 degrees, 60 degrees, and 80 degrees.

Front

What is the definition of a scalene triangle?

Back

A scalene triangle is a triangle with all sides of different lengths and all angles of different measures.