A sector of a circle has a radius of 10 cm and contains an angle of 150 degress. A hollow right circular cone is formed by bending the sector round until the bounding radii meet. Find the radius of the base of the cone and its semi-vertical angle.
A sector of a circle has a radius of 10 cm and contains an angle of 150 degress. A hollow right circular cone is formed by bending the sector round until the bounding radii meet. Find the radius of the base of the cone and its semi-vertical angle.