Geometry (16) the lengths of the sides of a sandbox are 9ft, 6ft and n ft. write a compound inequality that describes all possible lengths of n.

A = 9 and b = 6 are the two given sides

The third missing side n can be described through the following inequality
a-b < n < a+b
where a > b ('a' is larger than b)
This is the triangle inequality theorem

So,
a-b < n < a+b
9-6 < n < 9+6
3 < n < 15

3 < n < 15
(which means you can pick any number from 3 to 15 for n. You cannot pick 3. You cannot pick 15)