Chapter 14 — Area

Chapter 14 of the Class 8 Maths NCERT textbook (Ganita Prakash), "Area", teaches students how to measure and calculate the area of different shapes using unit squares and mathematical formulas, covering rectangles, triangles, parallelograms, rhombuses, trapeziums, and any polygon.

• Area from unit squares to formulas — Starting from covering shapes with unit squares, the chapter develops area formulas for rectangles, triangles, parallelograms, rhombuses and trapeziums, so each formula is grounded in the idea of counting square units.
• Breaking shapes apart — Any polygon can be split into triangles to find its total area, and dissection methods let a shape be rearranged into another while preserving area — a flexible, reasoning-first approach to measurement.
• Area is not perimeter — The chapter stresses that figures with the same perimeter can enclose very different areas (and vice versa), correcting the common intuition that a larger boundary must mean more space inside.

1. 01Area of a rectangle = length × width (measured in square units like cm²)
2. 02A diagonal divides a rectangle into two congruent triangles, each with area equal to half the rectangle
3. 03Area of a triangle = ½ × base × height, regardless of triangle type or position
4. 04Regions with the same perimeter can have different areas, and vice versa — perimeter is not indicative of area
5. 05Area of a parallelogram = base × height (using the perpendicular height, not the slant side)
6. 06Area of a rhombus = ½ × product of its diagonals
7. 07Area of a trapezium = ½ × height × (sum of the two parallel sides)
8. 08Any polygon can be divided into triangles to find its total area