QUADRILATERALS
The perimeter of a polygon is the sum of the lengths of its sides.
The perimeter of the quadrilateral in the figure above is 5 + 8 + 3 + 7 = 23.
The four interior angles of any quadrilateral add up to 360 degrees.
A rectangle is a parallelogram containing four right angles. Opposite sides are equal. The formula for the area of a rectangle is
Area = (Length)(Width)In the diagram above, ℓ = length and w = width, so area = ℓw.
Perimeter = 2(ℓ + w)