<Ul> <Li> Adjacent </Li> <Li> Vertical </Li> <Li> Complementary </Li> <Li> Supplementary </Li> <Li> Transversal </Li> </Ul> <Ul> <Li> Dihedral </Li> </Ul> <P> In plane geometry, an angle is the figure formed by two rays, called the sides of the angle, sharing a common endpoint, called the vertex of the angle . Angles formed by two rays lie in a plane, but this plane does not have to be a Euclidean plane . Angles are also formed by the intersection of two planes in Euclidean and other spaces . These are called dihedral angles . Angles formed by the intersection of two curves in a plane are defined as the angle determined by the tangent rays at the point of intersection . Similar statements hold in space, for example, the spherical angle formed by two great circles on a sphere is the dihedral angle between the planes determined by the great circles . </P> <P> Angle is also used to designate the measure of an angle or of a rotation . This measure is the ratio of the length of a circular arc to its radius . In the case of a geometric angle, the arc is centered at the vertex and delimited by the sides . In the case of a rotation, the arc is centered at the center of the rotation and delimited by any other point and its image by the rotation . </P>

The intersection of the two sides of an angle is called the angles