Question

The formula for perimeter is p = 2 l + 2 w. If the perimeter p of a rectangle is 200 mm (millimeters) and the width w = 30 mm, what is l?

A. 60mm
B. 140mm
C. 70mm
D. 100mm

Answer 1

C. 70mm

Explanation:

Hello!

According to the question perimeter equal to

2l + 2w

Then, P = 2l + 2w

Where,

• P means perimeter
• L = length
• W = width

P = 2l + 2w

Substitute the values

200 = 2l + 2(30)

Note: 2(30) means 2 • 30

200 = 2l + 60

Flip the equation

2l + 60 = 200

Substract 60 from both sides

2l + 60 - 60 = 200 - 60

2l = 140

Divide both sides by the coefficient of l which is 2

2l/2 = 140/2

l = 70

So, L = 70mm

Hopes this helps