Revision Notes for Class 8 Maths Chapter 14: Area

Condensed revision notes for Class 8 Maths Chapter 14: Area – Ganita Prakash textbook (the final Class 8 Maths chapter). These Class 8 Mathematics Chapter 14 notes are ideal for quick revision just before exams.

Last Updated: September 23, 2026

• Rectangle: Area = length × breadth. Square: Area = side².
• Triangle: Area = ½ × base × height.
• Parallelogram: Area = base × height (uses perpendicular height, not the slant side).
• Rhombus: Area = ½ × d₁ × d₂ (product of diagonals, halved).
• Trapezium: Area = ½ × (sum of parallel sides) × height.
• Regular hexagon: Area = (3√3/2) × side².
• Equilateral triangle: Area = (√3/4) × side².
• Scaling rule: if every linear dimension of a shape is scaled by k, its area scales by k² (e.g. doubling a square’s side quadruples its area).
• Path/border area: Area of path = Outer area − Inner area. For a uniform border of width d around an l×w rectangle: Area = 2d(l+w) + 4d².
• Crosspath area: Area = (horizontal strip) + (vertical strip) − (overlap square), to avoid double-counting the overlap.
• Midpoint triangle theorem: joining the midpoints of two sides of a triangle creates a smaller triangle with ¼ the area of the original.
• Varignon parallelogram: joining the midpoints of any quadrilateral’s four sides forms a parallelogram with exactly half the original quadrilateral’s area.
• Unit conversions: 1 in = 2.54 cm; 1 ft² = 144 in²; 1 km² = 1,000,000 m².

More on this chapter: NCERT Solutions for Class 8 Maths Chapter 14 | Extra Questions for Class 8 Maths Chapter 14 | Class 8 Maths Book | Formulas Handbook

Frequently Asked Questions

What is the difference between perimeter and area?
Perimeter is the total length of the boundary enclosing a shape, measured in linear units like metres, while area is the amount of surface enclosed within that boundary, measured in square units like square metres.

How is the area of a trapezium calculated, and why does the formula involve both parallel sides?
The area of a trapezium is calculated as half the sum of its two parallel sides multiplied by the height between them, because averaging the two parallel sides accounts for the trapezium being wider on one side than the other.

Written by Satish

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