Q25 of 37 Page 13

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


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"


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)




= 5×57


= 285 mm


Now, Area of each sector of the brooch





∴Area of each sector=


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