Question

${(y-20)}^0$ and ${(y+30)}^0$ are complementary angles of each other, then find the measure of each one.

Answer 1

Let $A={(y-20)}^{\circ }$ and $B={(y+30)}^{\circ }$ be the complementary angles.

$\Rightarrow A+B={90}^{\circ }$

$\Rightarrow y-20+y+30=90$

$\Rightarrow 2y=90-10=80$

$\Rightarrow y=\frac{80}{2}={40}^{\circ }$

$\therefore y={40}^{\circ }$