SECTOR of a Sphere. is the solid generated by the revolution of the sector of a circle about one of its radii; the other radius describing the surface of a cone, and the circular are a circular portion of the surface of the sphere of the same radius. So that the spherical sector consists of a right cone, and of a segment of the sphere having the same common base with the cone. Hence the solid content of it will be found by multiplying the base or spherical surface by the radius of the sphere, and taking one third of the product.