ISEE Upper Level Math : How to find the length of the side of an acute / obtuse triangle

Example Questions

Example Question #52 : Triangles

Which of the following could be the lengths of the three sides of a scalene triangle?

Explanation:

A scalene triangle, by definition, has three sides of different lengths. We can identify the scalene triangle by converting measures to the same unit. We will convert to inches in this case.

5 feet =  inches. This triangle can be eliminated, since two sides have length 60 inches.

7 feet =  inches. This triangle can be eliminated, since two sides have length 84 inches.

These three measures are equal. This is an equilateral triangle, and it can be eliminated.

feet =  inches. This triangle can be eliminated, since two sides have length 66 inches.

5 feet = 60 inches.

6 feet =  inches.

The sides of this triangle measure 60, 72, and 84 inches, so the triangle is scalene.