Answer
See the step-by-step proof below.
Work Step by Step
As indicated in the figure, $ h=c\cdot sinB=b\cdot sinC $ Thus we have
$\frac{sinB}{b}=\frac{sinC}{c}$
Similarly, if we draw a vertical line from point C to the opposite side, we get:
$\frac{sinB}{b}=\frac{sinA}{a}$
Hence, we derived the law of sines.
