Triangle Angle Relationships

Front

What is the Triangle Sum Theorem?

Back

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

Front

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

Back

It is a right triangle.

Front

What is the measure of the third angle if two angles of a triangle are 50° and 60°?

Back

The third angle measures 70°.

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

If two angles of a triangle are 45° each, what is the type of triangle?

Back

It is an isosceles triangle.

Front

What is the measure of an exterior angle of a triangle?

Back

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

Front

If angle A = 30° and angle B = 60°, what is angle C?

Back

Angle C = 90° (since 30° + 60° + C = 180°).

Front

What is the measure of an angle in an equilateral triangle?

Back

Each angle in an equilateral triangle measures 60°.

Front

If angle X = 40°, what is the measure of angle Y in a triangle where angle Z = 100°?

Back

Angle Y = 40° (since 40° + Y + 100° = 180°).

Front

What is the sum of the angles in a triangle?

Back

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