A quadrilateral is a four sided polygon. The sum of interior angles for all quadrilaterals must be equal to 360 degrees. There are five main types of quadrilaterals each having its own features.

Square

square

  • All sides are equal in length.
  • All angles are right angles.
  • Opposite sides are parallel.
  • Perimeter = 4 × (side) = 4 × L
  • Area = (Side) × (Side) = L × L

Rectangle

rectangle

  • Opposite sides are equal in length.
  • Opposite sides are parallel.
  • All angles are right angles.
  • Perimeter = 2 × (Length + Breadth) = 2 × (L + B)
  • Area = (Length) × (Breadth) = L × B

Parallelogram

parallelogram

  • Opposite sides are equal in length and parallel.
  • Opposite angles are equal.
  • Adjacent angles are supplementary.
  • The diagonals bisect each other.
  • Perimeter = 2 × (Length + Breadth) = 2 × (L + B)
  • Area = (Length) × (Height) = L × h

Rhombus

rhombus

  • All sides are equal in length (all angles are not equal).
  • Adjacent angles are supplementary.
  • Opposite angles are equal.
  • Diagonals bisect each other at right angles. 
  • Perimeter = 4 × (Side) = 4 × L
  • Area = (multiple of diagonals)/2

Trapezoid

trapezoid

  • Only one pair of sides is parallel.
  • Perimeter = Sum of sides = A + B + C + D
  • Area = (Height) × (Sum of parallel sides)/2 = (h) × (A + B)/2