Pope is putting a fence in his backyard to enclose a garden in a form of a triangle. The garden already has sides enclose with eight feet and five feet of fence, respectively. What can you about the length of the third side?

Explanation:

x represents the length of the third side so, 13>x>3, so i know this because there is a theorem that states that the length of one side of a triangle is less than the sum of the length of the other two sides, in other words (pretending the sides are A, B, and C) A<B+C, B<A+C, and C<A+B, so you do with this with x and the values you currently have: x<8+5, 5<8+x, and 8<x+5. then you simplify all of them for x, so you would get x<13, -3<x, and 3<x, and since -3 is less than 3 you disregard that value because if x is greater than 3 it is obviously greater than -3 (also because by doing this you help find the smallest value x can't be and putting -3 would make the answer incorrect because its too broad). so now that you have 13>x and 3<x you can arrange them like above to get 13>x>3