SAT Math: Find the area of a rectangle or square

The concept, explained

• 1

  Area of a rectangle = length × width. Area of a square = side². Units are always squared (in², cm²).

• 2

  Perimeter is different from area: perimeter = 2(length + width) for a rectangle, 4 · side for a square.

• 3

  For composite rectangular shapes, break the figure into non-overlapping rectangles, compute each area, and sum.

• 4

  When only a diagonal or one side is given, use the Pythagorean theorem or properties of the figure to find the missing dimension.