Students can go through AP Board 9th Class Maths Notes Chapter 11 Areas to understand and remember the concepts easily.

## AP State Board Syllabus 9th Class Maths Notes Chapter 11 Areas

→ The part of a plane enclosed by a simple closed figure is called a planar region corresponding to that figure.

→ The magnitude of a planar region is its area.

→ The unit area is the area enclosed by a unit square i.e. a square of side 1 unit.

→ Area is always expressed in square units.

→ The areas of two congruent figures are equal.

→ Converse of the above is not true, i.e., if two figures have same area, they need not be congruent.

→ The area of a whole figure is equal to sum of the areas of finite parts of it.

→ Area of a rectangle is equal to the product of its length and breadth.

→ Area of a parallelogram is the product of a side and its corresponding altitude.

→ Parallelograms on the same base and between same parallels are equal in area.

→ If a parallelogram and a triangle lie on a same base and between same parallels, then the area of the triangle is half the area of parallelogram.

→ Triangles between same base and between same parallels are equal in area.