Properties of Quadrilaterals

Parallelogram

  • Opposite sides: parallel & equal

  • Opposite angles: equal

  • Diagonals: bisect each other

Rectangle

  • All parallelogram properties

  • Each interior angle: 90∘90^{\circ}

  • Diagonals: equal & bisect each other

Rhombus

  • All parallelogram properties

  • All sides: equal

  • Diagonals: bisect at 90∘90^{\circ}

  • Diagonals: bisect opposite angles

Square

  • All rectangle & rhombus properties

  • All sides: equal

  • All angles: 90∘90^{\circ}

  • Diagonals: equal, bisect at 90∘90^{\circ}, bisect angles into 45∘45^{\circ} each

Kite

  • Two pairs of adjacent sides: equal

  • One diagonal (between equal sides):
    • Bisects other diagonal
    • Bisects interior angles
    • Axis of symmetry

  • Diagonals: intersect at 90∘90^{\circ}

  • One pair of opposite angles (between unequal sides): equal

Trapezium (General)

  • Exactly one pair of opposite sides: parallel

Isosceles Trapezium

  • One pair of opposite sides: parallel

  • Non-parallel sides: equal

  • Base angles: equal

  • Diagonals: equal