13. A round table cover has six equal designs as shown in Fig. . If the radius of the cover is 28 cm, find the cost of making the designs at the rate of Rs. 0.35 per cm2. (Use )
The angle of each of the six sectors is 60o at the centre.
Area of the sector is given by:-
or
or
And the area of the equilateral triangle associated with segment:-
or
Hence the area of segment is :
Thus the total area of design is :
So, the total cost for the design is:-