First, look at the side lengths a, b, and c, where c is the longest. Then take the sum of a squared and b squared and compare it to c squared. If they are equal, the triangle is a right triangle. If c squared is less than a squared plus b squared, the triangle is acute. If c squared is greater than a squared plus b squared, the triangle is obtuse.
1) The side lengths of the triangles determine which of these types the triangle is:
a) equilateral if all the sides are equal
b) isoscels if two sides are equal and one is different
c) scalene is the three sides are different.
2) The side lengths determine the angles. When you know the three sides you can use the cosine law to determine the angles. The type of triangle according to the angles is:
