Angles in a Triangle

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 do you call an angle that measures less than 90 degrees?

Back

An acute angle.

Front

What do you call an angle that measures exactly 90 degrees?

Back

A right angle.

Front

What do you call an angle that measures more than 90 degrees but less than 180 degrees?

Back

An obtuse angle.

Front

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

Back

It is a right triangle.

Front

In a triangle, if one angle measures 36 degrees and another measures 85 degrees, what is the measure of the third angle?

Back

The third angle measures 59 degrees (180 - 36 - 85 = 59).

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 exterior angle theorem?

Back

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

Front

If two angles of a triangle are equal, what can you say about the triangle?

Back

The triangle is isosceles.

Front

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

Back

Subtract the sum of the known angles from 180 degrees.