Question

If PA and PB are tangents from outside point P, such that PA$=10$cm and $\angle$APB$={60}^o$. Find the length of chord AB.

Answer 1

Given $PA=10cm,\angle APB={60}^o$

triangle $PAB$ is an isosceles triangle

So, $△OPA$ is a righgt angled triangle

$\angle OPA={30}^o$

Using sine rule, $\frac{\sin {30}^o}{AO}=\frac{\sin {90}^o}{10}$

$AO=5cm$

length of the chord $AB=2AO=10cm$