Question

A brooch is made with silver wire in the form of a circle with diameter 35mm. The wire is also used in making 5 diameters which divide the circle into 10 equal sectors as shown in the figure. Find: 

(i) the total length of the silver wire required. 

(ii) the area of each sector of the brooch

Answer 1

Here, brooch is made up of silver wire in the form of a circle.

The diameter of the brooch = 35mm

"⇒ The radius of the brooch, r" = 35/2 mm

Since the wire is used in making 5 diameters and circle

So,

The total length of the silver wire required = length of wire in circle + wire used in 5 diameters

= 2πr + 5 × 2r

= 2r(π + 5)