Question

4 circles are drawn side by side in a line and enclosed by a rectangle. If the radius of each of a circle is 3 cm. Then calculate 1. Area of a rectangle.
2. Area of a each circle.
3. The shaded area of inside the rectangle

Answer 1

(Refer to diagram)

According to question,

Four circles are enclosed within the rectangle.

And, diameter of each circle = 6cm

Therefore, AB = 6×4 cm = 24 cm

So, AB = CD = EF = 24 cm (since CDEF is a rectangle)

Now, CF = DE = diameter of each circle = 6cm

(1) area of rectangle CDEF = length × breadth units² = 24×6 cm² = 144 cm²

(2) area of each circle = πr² units² = 22/7 × (3)² cm² = 198/7 cm² = 28.28 cm²

Therefore, area of four circles = 28 × 4 cm² (for the convenience of calculation) = 112 cm²

(3) area of shaded region = (area of rectangle) - (area of four circles) units² = 144-112 cm² = 32 cm²