Related rates - how is the area of the triangle increasing

Question

The legs of an isoceles triangle are increasing at a rate of 16cm/s while the base of the triangle remains constant at 60cm. At what rate is the area of the triangle increasing when each leg is 50cm?

Answer 1

Area = A = sb = side x base

A' = (sb)' = sb' + bs' = 50(0) + (60)s' =0 + (60)(16) = 96 cm^2/sec