Before writing the C program to check whether the triangle is equilateral, we should know the properties of equilateral triangles. In geometry, an equilateral triangle is a triangle in which all three sides are equal.
int side1, side2, side3;
//Get sides of a triangle from the user
printf(“Enter sides of triangle\n”);
if((side1==side2) && (side2==side3))
//All sides are equal, so Equilateral triangle
printf(“Not a Equilateral triangle.\n\n”);