Shape of the universe at least two angles equal 90°, which makes the sum of the 3 angles greater than 180°. An example of a negatively curved surface would be the shape of a saddle or mountain pass. A triangle drawn on a saddle surface will have the sum of the angles adding up to less than 180°. General relativity explains that mass and energy bend the curvature of spacetime and is used to determine what curvature the universe has by using a value called the density parameter, represented with Omega (). The density parameter is the average density of the universe divided by
Triangle center if the trilinear coordinates of P can be expressed in the form f(A) : f(B) : f(C) where f(A) is a function of the angle A alone and does not depend on the other angles or on the side lengths. A triangle center P is called a "transcendental triangle center" if P has no trilinear representation using only algebraic functions of a, b and c. Let "f" be a triangle center function. If two sides of a triangle are equal (say "a" = "b") then so two components of the associated triangle center are always equal. Therefore all triangle centers