Exercise 77 Page 659

First, we want to determine whether the given set of numbers can be the measures of the sides of a triangle. To do that we will use the Triangle Inequality Theorem. We have to check if the sum of each two sides is greater than the third side.

3.2+5.3<& 8.6 * 3.2+8.6>& 5.3 ✓ 5.3+8.6>& 3.2 ✓ As we can see, the given side lengths cannot form a triangle, because the sum of 3.2 and 5.3 is less than 8.6.