Question

A triangle has two sides of lengths 7 and 9. What value could the length of the third side be?

Answer 1

The length of the third side could be all real numbers greater than 2 units and less than 16 units

Explanation:

we know that

The Triangle Inequality Theorem states that the sum of any 2 sides of a triangle must be greater than the measure of the third side.

so

Applying the triangle inequality theorem

Let

x ------> the length of the third side

we have

First case

1) 7+9 > x

16 > x

Rewrite

x< 16 units

Second case

2) 7+x > 9

x > 9-7

x > 2 units

therefore

The solution for the third side is the interval

(2,16)

All real numbers greater than 2 units and less than 16 units