Which set of lengths could not be the sides of a triangle? a) 9 inches, 12 inches, 21 inches) 9 inches, 11 inches, 12 inches) 12 inches, 14 inches, 16 inches) 16 inches, 18 inches, 25 inches. hurry for brainiest

If a, b and c are the lengths of the sides of a triangle then

if a ≤ b ≤ c, then a + b > c.

A) 9, 12, 21

9 + 12 = 21  YES :)

B) 9, 11, 12

9 + 11 = 20 > 12  NOT :(

C) 12, 14, 16

12 + 14 = 26 > 16  NOT :(

D) 16, 18, 25

16 + 18 = 34 > 25  NOT :(

c

step-by-step explanation: