Answer
$150\sqrt {3}$ $cm^{2}/min$
Work Step by Step
the area $A$ of an equilateral trigangle with side $s$ is given by
$A$ = $\frac{1}{4}\sqrt {3}s^{2}$
$\frac{dA}{dt}$ = $\frac{1}{4}\sqrt {3}(2s)\frac{ds}{dt}$
$\frac{dA}{dt}$ = $\frac{1}{4}\sqrt {3}(2)(30)(10)$
$\frac{dA}{dt}$ = $150\sqrt {3}$ $cm^{2}/min$
