Asked by Katie

If one side of a triangle is 10 inches long, which of the following could NOT be the lengths, in inches, of the other sides?
A. 2 & 9
B. 3 & 5
C. 5& 10
D. 10 & 10
E. 10 & 12

I think it might be B but I don't know and I don't know how to figure the answer.. please help!
Answered by drwls
B. The length of any side of a triangle must lie in a range between the sum and differnce of the other two sides.