You have already seen that two equilateral spherical triangles can have different angles. If α is the measure of an angle in an equilateral triangle on S₂ use the formula that gives the length of the side of a spherical triangle in terms of α to decide what value α cann ot ever exceed and one it can never go below. To phrase the question more precisely, if A is the set of all possible angles α, in a spherical equilateral triangle , find inf A and sup A
