The area is 30 square centimeters and a height with 10 centimeters. What is the length of the base?
So,
The formula for the area of a rectangle is:
A = l w
We will consider l to be the height.
Substitute the given values.
30 = 10 w or 10w
Divide both sides by 10.
3 = w
The length (I would call it the width, since it is shorter) of the rectangle is 3 centimeters.