Question

which set of side lengths does not form a triangle? all lengths are given in inches. (1 point)
18, 10, 8
9, 17, 11
11, 19, 9
18, 11, 8

Explanation:

Step1: Recall triangle - inequality theorem

The sum of the lengths of any two sides of a triangle must be greater than the length of the third side.

Step2: Check option 1 (18, 10, 8)

$10 + 8=18$, but in a triangle $a + b>c$, here $10 + 8$ is not greater than 18.

Step3: Check option 2 (9, 17, 11)

$9+11 = 20>17$, $9 + 17=26>11$, $11 + 17 = 28>9$.

Step4: Check option 3 (11, 19, 9)

$11+9 = 20>19$, $11 + 19=30>9$, $9 + 19 = 28>11$.

Step5: Check option 4 (18, 11, 8)

$11+8 = 19>18$, $11 + 18=29>8$, $8 + 18 = 26>11$.

Answer:

18, 10, 8