A triangle has side lengths of 11 cm and 7 cm. Which could be the value of the third side, 19 cm or 17 cm ?

17

Step-by-step explanation:

We are given the side lengths:

2

We check the triangle's inequalities if we add the third side of 20 cm:

3

Since one of the inequalities is not verified, the three given side lengths cannot form a triangle.

(Because the sum of two sides is equal to the third, we can say the triangle is degenerated to a segment.)

4

We check the triangle's inequalities if we add the third side of 15 cm:

5

Since all the three inequalities are verified, 15 can be the value of the third side.

RESULT - this one is 15 but the questions is move the 2 and it will give you 17

15 cm