Area and perimeter — Quantitative aptitude for kids

The method

Round and inside — “perimeter is the distance round a shape; area is the space inside it”

1. Rectangle: area = l × b, perimeter = 2 × (l + b). Square: area = side × side, perimeter = 4 × side.
2. Triangle: area = ½ × base × height.
3. Circle (π = 22/7): area = π × r × r, circumference = 2 × π × r.
4. Path outside a garden: (l + 2w) × (b + 2w) − l × b.

Use it for: Fencing, flooring, painting, gardens and mensuration questions in Class 6–10 and aptitude tests.

Worked example: A garden is 20 m long and 12 m wide. A path 2 m wide runs all round it, outside. What is the area of the path (in sq m)? → 144

✏️ Practice

Work it out in your head or on paper, type the answer and press Check. Stuck? Press “Show me how”.

🏁 Lesson 25 test

20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.

🏅 Sign in with Google to earn the 📐 Perimeter Pro badge when you pass — and a certificate when you finish all 10 lessons of Part 3 · Aptitude challenge. You can still take the test without signing in.

🖨️ Area and Perimeter Worksheet

• Worksheet set 1 (PDF)
• Worksheet set 2 (PDF)
• Worksheet set 3 (PDF)