Question

If two sides in one triangle are 9 and 21 , then the third side might be

a) 9
b) 11
c) 12
d) 13
please explain how you got the answer in details I'm completely lost

Answer 1

13

Explanation:

there is a rule that says that if you add any 2 sides, it should be more than the third. 9+21 is greater than 13. 21+13 is greater than 9. 13 is the only number which if you add 9 to it it will be greater than 21. 12 will equal 21, but it still wont work.

hope this helps :))