# CBSE Class 10-Mathematics: Chapter –12 Areas Related to Circles Part 21

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**Question 18:**

A round table cover has six equal designs as shown in the figure. If the radius of the cover is , find the cost of making the design at the rate of per . (Use )

**Answer:**

Area of one design

Area of equilateral

[Area of equilateral triangle with side a ]

Total cost

**Question 19:**

Find the area of the shaded region where ABCD is a square of side .

**Answer:**

Area of square ABCD

Diameter of each circle

Radius of each circle

Area of one circle

Area of the four circles

**Question 20:**

ABCD is a flower bed. If and . Find the area of the bed.

**Answer:**

Here, m and

Area of the flower bed (i.e., shaded portion)

area of quadrant of a circle of radius R of the quadrant of a circle of radius r