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 degrees.

Front

If one angle of a triangle is 90 degrees, what can you say about the other two angles?

Back

The other two angles must sum to 90 degrees, making the triangle a right triangle.

Front

How do you find the measure of the third angle in a triangle if you know the measures of the other two angles?

Back

Subtract the sum of the known angles from 180 degrees.

Front

If angle A = 79° and angle B = 43°, what is angle C?

Back

Angle C = 180° - (79° + 43°) = 58°.

Front

What is the measure of angle B if angle A = 150° and angle C = 63°?

Back

Angle B = 180° - (150° + 63°) = -33°, which is not possible in a triangle.

Front

What is the measure of angle b if angle a = 36° and angle c = 117°?

Back

Angle b = 180° - (36° + 117°) = 27°.

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 a triangle has angles measuring 25° and 55°, what is the measure of the third angle?

Back

The third angle = 180° - (25° + 55°) = 100°.

Front

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

Back

Each angle in an equilateral triangle measures 60°.

Front

If angle A = 67° and angle B = 54°, what is angle C?

Back

Angle C = 180° - (67° + 54°) = 59°.