the perimeter of a sector of acircle of radius 4.2cm is 12.8cm, find the area of the sector.
let the radius of the circle be r = 4.2 cm
let the arc length AB be p cm.
the perimeter of the sector AOB = p+2r
therefore, p+2r=12.8
p+2*4.2=12.8
p+8.4=12.8
p=12.8-8.4
p = 4.4 cm
the length of the arc = 4.4 cm
the circumference of the circle =
let the sector makes an angle θ with the center.
therefore
area of the sector =
hope this helps you.