Question

Which of the following are complementary angles?

• A.
• B.
• C.
• D.

Answer 1

Answer: (A), (B), (C)

Two angles are complementary if their sum is ${90}^{\circ }$.

${30}^{\circ }+{60}^{\circ }={90}^{\circ }$
$\Rightarrow$ Complementary angles
${45}^{\circ }+{45}^{\circ }={90}^{\circ }$
$\Rightarrow$ Complementary angles

$0^{\circ }+{90}^{\circ }={90}^{\circ }$
​​​​​​​$\Rightarrow$ Complementary angles

${90}^{\circ }+{90}^{\circ }\ne {90}^{\circ }$
​​​​​​​$\Rightarrow$ NOT complementary angles

Complementary angles need not be adjacent angles.