Triangle Sum and Exterior Angle Theorems

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 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 the Exterior Angle Theorem?

Back

The Exterior Angle Theorem states that the measure of an exterior angle of a triangle is equal to the sum of the measures of the two non-adjacent interior angles.

Front

Solve for x: If angle A = 50 degrees and angle B = 60 degrees, what is angle C?

Back

Angle C = 70 degrees (since 180 - 50 - 60 = 70).

Front

What is the formula to find the measure of an exterior angle?

Back

The measure of an exterior angle = measure of angle 1 + measure of angle 2 (the two non-adjacent interior angles).

Front

If angle A = 34 degrees and angle B = 66 degrees, what is angle C?

Back

Angle C = 80 degrees (since 180 - 34 - 66 = 80).

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

Solve for x: If angle A = 40 degrees and angle B = x degrees, what is angle C if angle C is an exterior angle?

Back

Angle C = 40 + x degrees.

Front

What is the sum of the angles in a triangle?

Back

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

Front

If angle A = 45 degrees and angle B = 45 degrees, what is angle C?

Back

Angle C = 90 degrees (since 180 - 45 - 45 = 90).