Your classmate is unsure about how to use side lengths to determine the type of triangle. how would you explain this to your classmate?

1) Equilateral Triangles: These triangles have the same side length and same angle for all sides. Knowing this, if the side lengths given are all the same, the triangle will be classified as an equilateral triangle. 

2) Isosceles Triangles: These triangles have two sides that have the same side length and one that is not the same. Given this, if the side lengths are all given, the triangle with two same sides are classified as isosceles triangle. 

3) Scalene Triangles: These triangles have all sides associated with a different value. If all side lengths are given and they have different values, this triangle would classify as a scalene triangle. 

Hope I helped :)