The perimeter p of a rectangle of sides `l\ a n d\ b` is given by `P=2\ (l+b)dot\ ` evaluate the variable and constant part

Explanation

The formula for perimeter of a rectangle is given as: `2times(l+b)`.
Therefore, by seeing this we can say that `2` is constant, whereas we use this formula for calculating perimeter of rectangles, each rectangles having different measures of their length and breadth. Therefore, we can say that `(l+b)` is the variable part.
Hence, `2` is the constant part and `(l+b)` is the variable part.