The rectangle has an area of 72m2, the length is twice the width. Determine the area of the rectangle.

First of all, we note that the answer to the question posed is in the description of the task itself. However, the experience of solving such problems prompts the following thought. Apparently they wanted to write “Determine the length and width of the rectangle.”
The area of the rectangle (S) is calculated by the formula S = a * b, where a is the length, b is the width of the rectangle.
If the length of the rectangle is twice its width, then a = 2 * b.
Then, 2 * b * b = 72 m2 or b ^ 2 = 36 m2, whence b = 6 m.
We have a = 2 * b = 2 * 6 m = 12 m.