Formulary: Maths - Geometry - Rectangle ▭

Rectangle ▭

A rectangle is a basic shape which has four right angles (90°).

Definitions:

  • a: Edge Length a
  • b: Edge Length b
  • d: Diagonal
  • U: Perimeter
  • A: Area
a U b

Perimeter of a Rectangle

The perimeter U is the total length of all 4 sides.

\( {\color{blue} {U}} = 2 \times {\color{red} {a} } + 2 \times {\color{OliveGreen} {b} } = 2 \times \left( {\color{red} {a} } + {\color{OliveGreen} {b} } \right) \)
U = Perimeter
a = Edge Length a
b = Edge Length b


a A b

Area of a Rectangle

The region inside a rectangle.

\( {\color{OliveGreen} {A}} = {\color{red} {a} } \times {\color{blue} {b} } \)
A = Area
a = Edge Length a
b = Edge Length b


a b d

Pythagorean Theorem

\( d=sqrt(a^2+b^2) \)
d = Diagonal
a = Edge Length a
b = Edge Length b

\( a=sqrt( d^2-b^2 ) \)
a = Edge Length a
d = Diagonal
b = Edge Length b

\( b=sqrt( d^2-a^2 ) \)
b = Edge Length b
d = Diagonal
a = Edge Length a