Question

If $\angle A$ is complement to ${30}^o$ and $\angle B$ is supplement to ${120}^o$ then:

• A. $\angle A>\angle B$
• B. $\angle A<\angle B$
• C. Incomparable
• D. $\angle A=\angle B$

Answer 1

Answer: (D)

$\angle A=\angle B$

Sum of complementary angles is ${90}^{\circ }$

$\Rightarrow \angle A+{30}^{\circ }={90}^{\circ }\Rightarrow \angle A={60}^{\circ }$

Sum of supplementary angles is ${180}^{\circ }$

$\Rightarrow \angle B+{120}^{\circ }={180}^{\circ }\Rightarrow \angle B={60}^{\circ }$

$\Rightarrow \angle A=\angle B$