R
Rishtaara
Mathematics · Class 7

Perimeter and Area

Area of parallelograms, triangles, circles, and perimeter of composite figures.

4 sections15–25 min read6 MCQs · 2 examples

Chapter Overview

Extend mensuration to parallelograms, triangles, and circles. Learn circumference and area of circle — applied to wheels, fields, and circular tracks.

Parallelogram and Triangle

Parallelogram area

A = base × height

Triangle area

A = ½ × base × height

Rhombus

A = ½ × d₁ × d₂

Circle

Circumference

C = 2πr = πd

Area

A = πr²

π

π ≈ 22/7 or 3.14

Conversions

  • 1 hectare = 10,000 m²
  • Break composite figures into known shapes

Solved Examples

Step-by-step solutions — read each step before checking the final answer.

Example 1: Circle Area

Radius of circular garden is 7 m. Find area.

  1. 1A = πr²
  2. 2= 22/7 × 7 × 7

Answer

154 m²

Example 2: Parallelogram

Base 12 cm, height 8 cm. Find area.

  1. 1A = b × h
  2. 2= 12 × 8

Answer

96 cm²

Key Points to Remember

  • Height must be perpendicular to base
  • Use correct π value as specified
  • Perimeter of circle = circumference

Exam Tips

  • Write π = 22/7 if radius multiple of 7
  • Include units in final answer

Practice MCQs — Perimeter and Area

Test your understanding with topic-wise multiple choice questions. Explanations appear after each answer.

Question 1 of 6Score: 0/0

Circumference of circle r=7 cm (π=22/7):