The side of a square in increasing at the rate of 0.2 cm/sec. Find the rate of increase of the perimeter of the square.

Explanation

Let the side of the square be `{x}`,


We have, `P=4 x` and `frac{d x}{d t}=0.2`


Now, `{P}=4 {x} Rightarrow frac{{dP}}{{dt}}=4 frac{{dx}}{{dt}} Rightarrow frac{{dP}}{{dt}}=4 times 0.2=0.8 {cm} / {sec}`