Define an enumeration type triangletype that has the values scalene, isosceles, equilateral, and notriangle. write a function triangleshape that takes as parameters three numbers, each of which represents the length of a side of the triangle. the function should return the shape of the triangle. (note: in a triangle, the sum of the lengths of any two sides is greater than the length of the third side.) write a program that prompts the user to input the length of the sides of a triangle and outputs the shape of the triangle.