The result of the cos-1 function in the formula is in radians. The formula uses the radius of the cylinder. R C 2p r C 2 p Once you know the radius you have the lengths of two of the parts of the sector.
Radius and height have the same unit eg.
Mathematically the part of the sphere with vertex at the center and conical boundary is the spherical sector. A radius is the distance between the center and the surface. S r2 h2. The formula we will use here is to find the volume and surface of the spherical sector.