angle addition

Front

What is the Angle Addition Postulate?

Back

The Angle Addition Postulate states that if point D is in the interior of angle ABC, then m∠ABD + m∠DBC = m∠ABC.

Front

If m∠ABC = 103°, what is the measure of angle ABD if m∠DBC = 15°?

Back

m∠ABD = m∠ABC - m∠DBC = 103° - 15° = 88°.

Front

Find x if m∠ABC = 103° and m∠ABD = x + 15°.

Back

x = 103° - 15° = 88°.

Front

What is the measure of angle A if m∠A + m∠B = 90° and m∠B = 65°?

Back

m∠A = 90° - 65° = 25°.

Front

If m∠A = 25° and m∠B = 30°, what is m∠C if m∠A + m∠B + m∠C = 180°?

Back

m∠C = 180° - (m∠A + m∠B) = 180° - (25° + 30°) = 125°.

Front

What is the sum of the angles in a triangle?

Back

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

Front

If m∠A = 90° and m∠B = 45°, what is m∠C?

Back

m∠C = 180° - (m∠A + m∠B) = 180° - (90° + 45°) = 45°.

Front

What is a complementary angle?

Back

Two angles are complementary if the sum of their measures is 90°.

Front

What is a supplementary angle?

Back

Two angles are supplementary if the sum of their measures is 180°.

Front

If m∠A = 82°, what is the measure of its complement?

Back

The complement of m∠A = 90° - 82° = 8°.