WAEC - Mathematics (1995 - No. 30)
The angle of a sector of a circle is 108°. If the radius of the circle is 31/2cm, find the perimeter of the sector
6 3/5cm
6 4/5cm
7 1/10cm
10 2/5cm
13 3/5cm,
توضیح
Perimeter of sector = \(\frac{\theta}{360°} \times 2\pi r + 2r\)
= \(\frac{108}{360} \times 2 \times \frac{22}{7} \times \frac{7}{2} + 2(\frac{7}{2})\)
= \(6 \frac{3}{5} + 7\)
= \(13 \frac{3}{5} cm\)