First, let's find the clues that the question provides.
From the diagram, we know that the length of sides AB & CD are equal, that is, AB=CD since this is the property of a rectangle where they are parallel sides of the same length. Therefore:
Next, the question also tells you the area of the rectangle. The area of a rectangle is given by the formula, Area = Length x Heights. So, we can say that multiplying the side AB, which is the length, with side AD gives you the area:
Hope this helps!