# How do you find the area of triangle ABC given A=138^circ, b=10, c=20?

$66.91 s q . u n i t s \left(4 \mathrm{dp}\right) .$
The Area of $\Delta A B C = \frac{1}{2} b c \sin A = \left(\frac{1}{2}\right) \left(10\right) \left(20\right) \sin {138}^{\circ}$
$\approx \left(100\right) \left(0.6691\right) = 66.91 s q . u n i t s \left(4 \mathrm{dp}\right) .$