A 240 degree sectors of a circle of a radius 14cm is bent to form a cone.find the radius of the base of the cone and it vertical angle

length of arc of base = (240/360) * 2 * pi * 14 = (2/3) * 28 pi = 58.6 cm

that is the circumference of the base of the cone
2 pi Rcone = 58.6
Rcone = 9.33 cm
slant height = 14 cm
sin (Theta/2) = 9.33 /14
Theta/2 = 41.7
Theta = 83.6 deg