Classify quadrilaterals

Key notes:

Definition:

• A quadrilateral is a polygon with four sides, four angles, and four vertices.

Types of Quadrilaterals

1. General Quadrilaterals:
   • Any four-sided figure (e.g., trapezoids, irregular shapes).
2. Parallelograms:
   • Opposite sides are parallel and equal in length.
   • Opposite angles are equal.
   • Diagonals bisect each other.
   • Examples: Rectangle, Rhombus, Square.
3. Rectangle:
   • A type of parallelogram.
   • All angles are right angles (90 degrees).
   • Opposite sides are equal and parallel.
4. Rhombus:
   • A type of parallelogram.
   • All sides are equal in length.
   • Opposite angles are equal.
   • Diagonals bisect each other at right angles.
5. Square:
   • A special type of rectangle and rhombus.
   • All sides are equal, and all angles are right angles.
   • Diagonals are equal and bisect each other at right angles.
6. Trapezoids (Trapeziums):
   • At least one pair of opposite sides is parallel.
   • Can be classified as:
     • Isosceles Trapezoid: Non-parallel sides are equal in length, and base angles are equal.
     • Right Trapezoid: Contains two right angles.
7. Kite:
   • Two pairs of adjacent sides are equal.
   • One pair of opposite angles is equal (angles between unequal sides).
   • Diagonals intersect at right angles.