Question

If side x has a length of 15 cm and side y has a length of 4 cm, then which value below could be the length of side z?

A.
20 cm
B.
21 cm
C.
17 cm
D.
10 cm

Answer 1

Explanation:

You should start with 10. The problem with 10 is that if you add 4 to it, the sum is less than 15, so no triangle will form.

A and B won't work either 4 + 15 is 19. A and B are both longer than 19 so no triangle will form.

The answer has to be C. 4 and 15 make 19. That's more than 17 so a triangle will be formed.