Question

Angles A and B are complementary. Angle A is 87°. Find the
measure of angle B.

Answer 1

m∠B = 3°

Explanation:

Complementary angles when combined will equal 90° in total.

∠A + ∠B = 90

m∠A = 87° {Given}

Plug in 87 for ∠A in the given equation, and solve for ∠B

87 + ∠B = 90

Isolate the variable. Subtract 87 from both sides of the equation:

87 (-87) + ∠B = 90 (-87)

∠B = 90 - 87

∠B = 3°

m∠B = 3° is your answer.

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