Given: If the length and breadth of a rectangle are in the ratio 3 : 2 and its perimeter is 20 cm. Concept used: Area of rectangle = Length × Breadth Perimeter of rectangle = 2(Length + Breadth) Calculation: Let the length of the rectangle be 3x Breadth of the rectangle be 2x. Area of the rectangle will be 6x2. Perimeter of the rectangle is 2(L+B) Perimeter =2(3x+2x) Perimeter = 10x ⇒10x=20 ⇒x=2 Length = 6cm and Breadth = 4 cm Area of rectangle =6x2 ⇒ Area =6×4 ∴ Area =24cm2 .