The height of a right cylinder is 2.5 times its radius. If the surface area of the cylinder is 122pi cm^2 , what is the radius of the cylinder in centimeters?
Surface area = 2 * pi * r^2 + 2pi * r * h
122 pi = 2 * pi * r ^2 + 2 pi * r * 2.5 r
122 pi = pi r^2 ( 2 + 2 *2.5)
122 = r^2 ( 7 )
122/ 7 = r^2
r = sqrt [ 122 / 7 ] cm ≈ 4.175 cm
its actually 4
+52 
