Question

Find the radius of a circle in which the central angle of (pie /4 ) radian determines a sector with an area of 86m^2

Answer 1

Area of sector  = 1/2 * r^2 * x   where r = radius and x = angle in radians

86 = 1/2 * r^2 * pi/4

r^2 = 2 * 86 * 4  / pi  =  219

r =  sqrt 219

= 14.80