Question

If $\sin {\left(A+20\right)}^o=\frac{\sqrt{3}}{2}$, then find value of $A$,

Answer 1

$\sin (A+{20}^o)=\frac{\sqrt{3}}{2}$

or, $\sin (A+{20}^o)=\sin {60}^o$

or, $A+{20}^o={60}^o$

$\therefore A={40}^o$