Solid angle and plane angle: A solid angle is a 3D angular volume that is defined analogously to the explanation of a plane angle in two dimensions.
In Euclidean geometry, an angle is the diagram formed by two rays, called the sides of the angle, sharing a common endpoint, called the angle’s vertex. Angles formed by two rays lie in the plane that contains the rays. The intersection of two planes also develops Angles. These are called dihedral angles.
A plane angle is distinguished by two straight lines bisecting at a point. The space between these lines in the plane defined by them is the plane angle.