2D Figure Formulas

Reguar Polygon

A "Regular Polygon" has: ** all sides equal and ** all angles equal.

Area of a Rectangle

Area of Rectangle =length x width

Area of a Triangle

Area of Triangle = base x height / 2 OR Area of Triangle = 1/2 (base * height)

Area of a Parallelogram

Area pf Parallellogram =base x height

Area of a Regular Polygon

Polygon Area= ap/2 a (apothem) = a line to the center of a side to the center of the polygon p (perimeter) = of sum of the side (s) of the polygon

Radius

measure across half of the circle Radius =D/2 or Radius=1/2 x D

Diameter

measure across the whole circle Diameter = 2 x radius or (D=2r)

Perimeter of a Polygon

perimeter = length of side x n (where "n" = the number of sides the polygon has). Perimeter = a+b+c+....... (add up all the sides)

Area

the amount of square units that can fit inside of a shape.

Perimeter

the distance around all of a shape

Circumference of Circle

π x diameter

Area of a Circle

π x radius^2 (radius squared)