Chapter 14 — Area

Chapter 14 of Class 8 maths, "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.

This chapter introduces area as a measure of space using unit squares and develops formulas for calculating areas of key shapes: rectangles (length × width), triangles (½ × base × height), parallelograms (base × height), rhombuses (½ × product of diagonals), trapeziums (½ × height × sum of parallel sides), and any polygon by breaking it into triangles. Students also explore dissection methods to transform shapes while preserving area and learn why perimeter alone cannot indicate area.

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