You can use the side lengths of a triangle to determine the type of triangle by comparing the lengths of the three sides. Here are the three types of triangles and how they are classified based on their side lengths:
1. Equilateral triangle: An equilateral triangle has three equal sides. If all three sides of a triangle are the same length, then it is an equilateral triangle.
2. Isosceles triangle: An isosceles triangle has two sides that are equal in length. If two sides of a triangle are the same length, then it is an isosceles triangle.
3. Scalene triangle: A scalene triangle has no sides that are equal in length. If all three sides of a triangle are different lengths, then it is a scalene triangle.
By comparing the side lengths of a triangle, you can determine which of these three types of triangles it is.