Question

If m∠4 = 35, find m∠3. Explain.

145; ∠3 and ∠4 are supplementary angles, so m∠3 = 180 − m∠4.

55; ∠3 and ∠4 are complementary angles, so m∠3 = 90 − m∠4.

35; ∠3 and ∠4 are corresponding angles, so m∠3 = m∠4.

35; ∠3 and ∠4 are alternate interior angles, so m∠3 = m∠4

Answer 1

55; ∠3 and ∠4 are complementary angles, so m∠3 = 90 − m∠4.

Explanation:

Complementary angles are a pair of two angles that add up to give us 90°.

Thus, angle 4 and angle 3 are complementary angles.

m∠ACD = 90°, m∠4 = 35°, therefore,

m∠ACD = m∠4 + m∠3.

Thus:

90° = 35° + m∠3

Subtract 35 from both sides

90 - 35 = 35° + m∠3 - 35

55 = m∠3

m∠3 = 55°.