RBSE Class 7 Maths Notes Chapter 11 Perimeter and Area

These comprehensive RBSE Class 7 Maths Notes Chapter 11 Perimeter and Area will give a brief overview of all the concepts.

RBSE Class 7 Maths Chapter 11 Notes Perimeter and Area

→ Perimeter is the distance around a closed figure whereas area is the part of plane occupied by the closed figure.

→ Area of rectangle = Length × Breadth

→ Perimeter of a rectangle = 2(Length + Breadth)

→ Breadth of a rectangle = \(\frac{\text { Area }}{\text { Length }}\)

→ Length of a rectangle = \(\frac{\text { Area }}{\text { Breadth }}\)

→ Perimeter of square = 4 × side

→ Area of a square = side × side

→ Side of a square = \(\sqrt{\text { Area of a square }}\)

→ Area of a parallelogram = base × height

→ Area of a triangle = \(\frac{1}{2}\) × base × height

→ Area of all congruent triangles is same, but it is not necessary that triangles having equal area will be congruent.

→ The distance around a circular region is known as its circumference.

→ Circumference of a circle = πd, where d is the diameter of a circle and π = \(\frac{22}{7}\) or 3.14 (approximately).

→ Area of a circle = πr², where r is the radius of the circle.

→ Area of path is obtained by subtractions area of inner rectangle or square from the area of outer rectangle or square.

→ Conversion of units of area :

• 1 cm² = 100 mm²
• 1 m² = 10000 cm²
• 1 hectare = 10000 m²

→ To find area of path:

• Area of path along the boundary of a rectangle.
  Square or circle = Area including path - Area excluding path.
• Area of path parallel to length/breadth = Length of parallel side × Width of path.
• Area of path parallel to length and breadth and intersecting each other = Area of both paths - Area of common path.