write in c++ program:  Write a program that determines the type of triangle for the given lengths of the sides:  the triangle does not exist,  an equilateral triangle,  an isosceles triangle,  A general triangle. Input: Three real numbers are the lengths of the sides of the triangle. Output: Depending on the type of triangle, output one of the following messages: 1. Triangle does not exist. 2. Triangle is equilateral. 3. Triangle isosceles Triangle of general form.