It is possible to define a trigonometry that is based on a shaper other than the unit circle. We define a new function called diamond-sine. It will be based on a square, the corners of the square will intersect the axes at points that are one unit from the origin. Let diamond-sin(t) give the y-coodinate of a point that is t units counterclockwise along the perimeter of the diamond from the point (1,0)