Question

HELP, thanks, If a triangle has a side length of 8 inches, and another side length of 5 inches, which of the

following choices for the third side length will make a triangle?
a. 7 inches
b. 2 inches
c. 13 inches
d. 15 inches

Answer 1

a. 7

Explanation:

So a triangle a two sides that will always sum up to be greater than the third side.

Meaning:

a + b > c

a + c > b

b + c > a

So here, we're given a and b:

8 + 5 > c

8 + c > 5

5 + c > 8

Plug in the values:

13 > 7

15 > 5

12 > 8

These are all true, so it's probably 7.

13 > 2

10 > 5

7 > 8 This one is not true, so not 2.

13 > 13 This is not true, so not 13.

If not 13, we can't go any higher and so it can't be 15.