Question

Question 9 (ii)
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:
(ii) The area of each sector of the brooch.

Answer 1

Number of diameters = 5
Length of diameter = 35 mm
$\therefore Radius=\frac{35}{2}mm$
(ii) Number of sectors = 10
$Areaofeachsector=\frac{Totalarea}{Numberofsectors}$
$Totalarea=\pi r^2=\frac{22}{7}\times (\frac{35}{2}{)}^2=\frac{1925}{2}m{m}^2$
$\therefore$ Area of each sector $=\left(\frac{1925}{2}\right)\times \frac{1}{10}=\frac{385}{4}m{m}^2$