Answer:
55; ∠3 and ∠4 are complementary angles, so m∠3 = 90 − m∠4.
Step-by-step 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°.