Question

Determine which of the following cannot be a triangle.
A. 3cm, 8cm, 12cm
B. 7cm, 8cm, 14cm
C. 10cm, 12cm, 21cm
D. 6cm, 10cm, 15cm

Answer 1

the sum of the smaller sides must at least the length of the greatest side

Answer 2

the sum of any two sides must be greater than the third...

Answer 3

so, option A

Answer 4

use Pythagoras Theorm

Answer 5

c'mon @Arnab09 , give the person time to try to figure out what the answer is before blurting it out. Giving the answer is not very helpful.

Answer 6

another thing to check, modulus difference of 2 sides must be less than the third side

Answer 7

ok, @Hero

Answer 8

or visit - http://www.cut-the-knot.org/pythagoras/index.shtml
hope it helps

Answer 9

@Jasminebunnies go through the link!