Protractor on the dial from 180°, as the dial is graduated from opposite zero marks to 90° each way. Since the spaces, both on the main scale and the Vernier scale, are numbered both to the right and to the left from zero, any angle can be measured. The readings can be taken either to the right or to the left, according to the direction in which the zero on the main scale is moved. Reading the Vernier scale: The bevel protractor Vernier scale may have graduations of 5′ (minutes) or 1/12°. Each space on the Vernier scale is 5′ less
Foundations of geometry his system he called Euclidean geometry "parabolic", a term which has not survived the test of time and is used today only in a few disciplines.) His influence has led to the common usage of the term "non-Euclidean geometry" to mean either "hyperbolic" or "elliptic" geometry. There are some mathematicians who would extend the list of geometries that should be called "non-Euclidean" in various ways. In other disciplines, most notably mathematical physics, where Klein's influence was not as strong, the term "non-Euclidean" is often taken to mean "not" Euclidean. For two thousand years, many attempts were made to prove the