Question

OAB is a sector of a circle with centre O and radius 8 cm.
Angle AOB = e°
The area of the sector is 58 cm2
Calculate the perimeter of the sector.
Give your answer correct to 3 significant figures.

Answer 1

Answer:

The perimeter of the sector is :30.5 cm

Step-by-step explanation:

Mathematically, we have the area of the sector as;

e/360 * pi * r^2

r is 8 cm

so we have

58 = e/360 * pi * 8^2

58/64 * 360/pi = e

e = 103.85

To get the perimeter,

we have length of the arc plus 2r

Length of the arc is;

e/360 * 2 * pi * r

add 2 r;

e/360 * 2 * pi * r + 2r

so we have

103.85/360 * 2 * pi * 8 + 2(8)

= 14.5 + 16

= 30.5 cm