# Thread: Finding area and angles with sine ratio

1. ## Finding area and angles with sine ratio

The area of acute-angled isosceles triangle PQR is 8cm squared. PQ = QR = 6cm. Find angle PQR to 2 decimal places.

I tried it and got 4/9, but its not right. Please help.
Thankyou

2. You just didn't finish.

$Area = \frac{1}{2}a^{2}sin{\theta}=8$

$18sin{\theta}=8$

$sin{\theta}=\frac{4}{9}$

${\theta}=sin^{-1}(\frac{4}{9})$