Question

1. in the figure below, the measure of ∠a is 70°. what is the complement of ∠a?

a) 10°
b) 20°
c) 80°
d) 110°
e) 130°

Explanation:

Step1: Recall the definition of complementary angles

Complementary angles add up to \(90^{\circ}\). Let the complement of \(\angle a\) be \(x\). Then \(x+\angle a = 90^{\circ}\).

Step2: Substitute the value of \(\angle a\)

Given \(\angle a=70^{\circ}\), substitute into the equation \(x + 70^{\circ}=90^{\circ}\).

Step3: Solve for \(x\)

Subtract \(70^{\circ}\) from both sides: \(x=90^{\circ}-70^{\circ}\).

Answer:

\(20^{\circ}\), so the answer is B.