The perimeter of a rectangle is 42 cm and it's length is x cm. Find it's width in term of x

Answer 1

Let the width of the rectangle be y cm.

Perimeter of a rectangle = 2(length + width)

Given:
Perimeter = 42 cm
Length = x cm

So, 42 = 2(x + y)
=> 42 = 2x + 2y
=> 21 = x + y
=> y = 21 - x

Therefore, the width of the rectangle in terms of x is 21 - x cm.