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.