This routine tests if the given triangle ABC is a right triangle. It returns true if ABC is a right triangle; false if it is not; and FAIL if it is unable to reach a conclusion.

If FAIL is returned, and the optional argument is given, the condition that makes ABC a right triangle is assigned to this argument. It will be either of the form  or of the form  where expr, expri_i are Maple expressions.

The command with(geometry,IsRightTriangle) allows the use of the abbreviated form of this command.

IsRightTriangle:   "hint: one of the following conditions must be satisfied: {-4*b = 0, -8+4*b = 0, -2-2*b^2+4*b = 0}"