# Revision Notes For CBSE Class 9 Math Chapter -9 Areas of Parallelograms and Triangles

A parallelogram is a quadrilateral with two pairs of parallel sides. The opposite sides of a parallelogram are equal in length & opposite angles are equal in measures. The Area of a parallelogram is given by the formulae:

Area = base Ã— height

A triangle is a plane figure with three straight sides and three angles. The sum of angles of a triangle is equal to 180 degrees and the exterior angles of a triangle are always equal to 360 degrees. In a triangle, the sum of the angles is always greater than the length of the third angle. The area of a triangle is given by the formulae:

Â½ * base * height.

## Frequently asked Questions on CBSE Class 9 Maths Notes Chapter 9: Areas of Parallelograms and Triangles

### What is a â€˜Parallelogramâ€™?

A quadrilateral with opposite sides parallel and equal is called as a Parallelogram.

### What are the uses of â€˜Trianglesâ€™?

Triangles are used in supporting the structure of the bridges because they evenly distribute the weight without changing the proportions. This is just one example where triangles are used.

### What is the meaning of a â€˜Formulaâ€™?

The formula is a fact or a rule written with mathematical symbols.