Question

Two sides of a triangle have lengths 11 and 18. What must be true about the length of the third side?

less than 29
less than 18
less than 33
less than 11

Answer 1

It must be less than 29 units in length.

Explanation:

The length of the third side of a triangle must be less than the sum of the lengths of the first two sides. Since 11+18=29, the third side must be less than 29 units in length.

Answer 2

less than 29

Explanation:

The smallest side cannot be smaller than the difference of the other two sides

18-11 = 7

and it cannot be larger than the sum of the other two sides

18+11 =29

Let s be the other side

7 < s < 29