Verified Answer :

30/10=3 3 cm is the length.

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.