Geometry Formulae
Square
Perimeter of a Square: 4 x side
Area of a Square: side × side = side 2
Rectangle
Perimeter of a Rectangle: 2 x (length + width) square
unit
Area of a Rectangle: length x width
Circle
Diameter of a Circle: 2 × r
Circumference of a Circle: 2 × π × r
Area of a Circle: π × r2
Triangle
Perimeter of a Triangle: side a + side b + side c
Area of a Triangle: ½ x base of the triangle x height of
the triangle.
Square
Perimeter of a Square: 4 x side
Area of a Square: side × side = side 2
Rectangle
Perimeter of a Rectangle: 2 x (length + width) square
unit
Area of a Rectangle: length x width
Circle
Diameter of a Circle: 2 × r
Circumference of a Circle: 2 × π × r
Area of a Circle: π × r2
Triangle
Perimeter of a Triangle: side a + side b + side c
Area of a Triangle: ½ x base of the triangle x height of
the triangle.