Which of the following can be the side lengths of a triangle? a: 12,9,21 b: 7,6,12 c: 3,8,14 d: 23,13,37

In a triangle the sum of two sides is always greater than the third side.

A:12,9,21
12+9 = 21
21 = 21  ⇒  no

B:7,6,12
7+6 = 13
13 > 12  ⇒  yes

C:3,8,14
3+8 = 11
11 < 14  ⇒  no

D:23,13,37
23+13= 36
36 < 37  ⇒  no

 B:7,6,12

55. i don’t no. but zhongshan