Question

Two circles intersects each other at points $A$ and $B$. $AP$ and $AQ$ are diameter of the two circles respectively. If $\angle APB={40}^o$ and $\angle AQB={70}^o$, find $\angle PAB$ and $\angle QAB$.

Answer 1

REF.Image

As angle by diameter on circle is ${90}^{\circ }$

$\Rightarrow \angle ABP=\angle ABQ={90}^{\circ }$

$\angle PAB={90}^{\circ }-\angle APB=90-40={50}^{\circ }$

$\angle QAB={90}^{\circ }-\angle AQB=90-70={20}^{\circ }$

( sum of angle in triangle = ${180}^{\circ }$)