

$$2p = 2b + 2S$$
Perimeter
$$b = \frac{2p  2S}{2}$$
Base
$$S = \frac{2p  2b}{2}$$
Oblique Side
$$A = b \times h$$
Area
$$b = \frac{A}{h}$$
Base
$$h = \frac{A}{b}$$
Height
Definition
A parallelogram is a quadrilater with opposite sides parallel (and congruent)
Properties
 Opposite sides are congruent and parallel
 Opposite angles are congruent, consecutive angles are supplementary (their sum is 180°)
 Diagonals intersect in their midpoint