About Quadrilaterals

A quadrilateral is a polygon with four sides and four vertices. There are several special types of quadrilaterals:

• Rectangle: All angles are 90°, opposite sides are equal
• Square: All sides are equal, all angles are 90°
• Parallelogram: Opposite sides are parallel and equal
• Rhombus: All sides are equal, opposite angles are equal
• Trapezoid: One pair of parallel sides

Formulas

• Area of Rectangle: A = length × width
• Area of Square: A = side²
• Area of Parallelogram: A = base × height
• Area of Rhombus: A = base × height = (d₁ × d₂)/2
• Area of Trapezoid: A = (base₁ + base₂) × height/2
• Perimeter: Sum of all sides