Parallelograms Summary

Quadrilateral

A plane closed figure formed by four line segments is called a quadrilateral

ABCD is a quadrilateral and written as quad. ABCD.

Various types of quadrilaterals

Parallelogram

A quadrilateral in which opposite sides are parallel is called a parallelogram.

Rectangle

A parallelogram each of whose angle is 90⁰ and opposite sides are equal is called a rectangle.

Square

A rectangle having all sides equal is called a square.

Rhombus

A parallelogram having all sides equal is called a Rhombus.

Trapezoid

A quadrilateral in which two opposite are parallel and two opposite sides are non parallel is called a trapezoid.

Kite

A quadrilateral in which two pairs of adjacent sides are equal is known as kite.

Properties of parallelograms

• A diagonal of a parallelogram divides it into two congruent triangles.

• In a parallelogram, the opposite sides are equal.

• In a parallelogram, the opposite angles are equal

• In a parallelogram, the diagonals bisect each other.

Properties of quadrilaterals

• In a quadrilateral, if opposite sides are equal, it is a parallelogram.

• In a quadrilateral, if opposite angles are equal, it is a parallelogram.

• In a quadrilateral, if diagonals bisect each other, it is a parallelogram.