Question

Which of the following could be the lengths of three sides of a triangle?

A) 3, 4, 5


B) 2, 5, 8


C) 2, 12, 15


D) 3, 3, 7

Answer 1

For three numbers to represent lengths of the sides of a triangle, the sum of each pair must be greater than the remaining side.

A)
3 + 4 = 7
3 + 5 = 8
5 + 4 = 9

B)
2 + 5 = 7
2 + 8 = 10
5 + 8 = 13

C)
2 + 12 = 14
2 + 15 = 17
15 + 12 = 27

D)
3 + 3 = 6
3 + 7 = 10
3 + 7 = 10

In all these, only A have the sum of the numbers greater than the numbers itself. So the answer is A.