Question

The perimeter of a rectangle is 20 m and the length is x m. Find the area of the rectangle in terms of x

Answer 1

$\huge\mathcal\pink{Question:-}$

The perimeter of a rectangle is 20 m and the length is x m. Find the area of the rectangle in terms of x

$\huge\mathcal\pink{Answer:-}$

Let the other side of the rectangle be x. Then,

2(x+y) = 20

x+y = 10

y = 10 - x (we express the other side in terms of x)

A = x(10-x) = -x^2 +10x

A will be maximized when the rectangle has equal sides, hence a square. Remember that every square is also a rectangle.

maximum area is 5×5 = 25 m^2