Question

9. A brooch is niade with silver wire in the form of a
circle with diameter 35 mm. The wire is also used in
making 5 diameters which divide the circle into 10
equal sectors as shown in Fig. 12.12. Find :
(i) the total length of the silver wire required
(ii) the area of each sector of the brooch
Fig. 12.12



Plzz tell fast ​

Answer 1

Answer:

9. A brooch is niade with silver wire in the form of a

circle with diameter 35 mm. The wire is also used in

making 5 diameters which divide the circle into 10

equal sectors as shown in Fig. 12.12. Find :

(i) the total length of the silver wire required

(ii) the area of each sector of the brooch

Fig. 12.12

Plzz tell fast

Answer 2

(1) Diameter of the Brooch =35 mm
Radius of brooch = 35/2 mm

Since wire is used in making 5 diameter and circle

Total wire used = length of wire in circle + wire used in 5 diameters


LENGHT OF WIRE IN CIRCLE

Length of wire in circle = circumference of circle
= 2 pie r
= 2*22/7*35/2
= 22*5
= 110

Silver wire used in 5 diameter= 5* diameter of circle
= 5*35
= 285 mm


(2) since the wire divides circle into 10 equal sectors
Area of all sectors of the brooch = 1/10 * area of all sectors of the brooch

Area of all sectors of the brooch = Area of circle
= pie r square
= 22/7 * (35/2) square
= 22/7 *35/2*35/2
= 11*5*35/2


Area of each sector of the brooch =
1/10 *Area of all sectors of the brooch
= 1/10 * 11*5*35/2
= 385/4 mm square

Therefore, area of each sector = 385/4 mm square