Answer: Option 'D' is correct.
Explanation:
We are required to find that length of sides which cannot be sides of triangle,
As we know that " Sum of two sides is always greater than the third side "
If any option does not follow the above postulate that will be our required answer :
D) 21 m, 6 m, 10 m
So, 21 m, 6 m, 10 m cannot be the length of any triangle as it does not satisfy the above mentioned postulate .
