Triangle Sum Theorem

Front

What is the Triangle Sum Theorem?

Back

The Triangle Sum Theorem states that the sum of the interior angles of a triangle is always 180°.

Front

If one angle of a triangle is 90° and another is 45°, what is the measure of the third angle?

Back

The third angle measures 45° (90° + 45° + 45° = 180°).

Front

What is the measure of angle a if angle b is 36° and angle c is 64°?

Back

Angle a measures 80° (36° + 64° + a = 180°).

Front

In a triangle, if two angles are equal, what can be said about the triangle?

Back

The triangle is isosceles.

Front

What is the measure of angle x if angle y is 50° and angle z is 70°?

Back

Angle x measures 60° (50° + 70° + x = 180°).

Front

If a triangle has angles measuring 30°, 60°, and x°, what is the value of x?

Back

x = 90° (30° + 60° + x = 180°).

Front

What is the relationship between the angles in a right triangle?

Back

In a right triangle, one angle is 90°, and the sum of the other two angles is 90°.

Front

If angle A is 40° and angle B is 70°, what is angle C?

Back

Angle C measures 70° (40° + 70° + C = 180°).

Front

What is the measure of the third angle in a triangle if the first two angles are 45° and 45°?

Back

The third angle measures 90° (45° + 45° + 90° = 180°).

Front

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

Back

Subtract the sum of the known angles from 180°.