Question

Question 9 (i)
A brooch is made 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.

Answer 1

Number of diameters = 5
Length of diameter = 35 mm
$\therefore Radius=\frac{35}{2}mm$
(i) Total length of silver wire required = Circumference of the circle + Length of 5 diameter
$=2\pi r+(5\times 35)mm$
$=(2\times \frac{22}{7}\times \frac{35}{2})+175mm$
$=110+175mm=285mm$