If 10 and 15 are the lengths of two sides of a triangular region, which of the following can be the ...

If 10 and 15 are the lengths of two sides of a triangular region, which of the following can be the length of the third side? I. 10 II. 15 III. 25

Quiz

Answer/Solution

I and II only

Steps/Work

The length of any side of a triangle must be larger than the positive difference of the other two sides, but smaller than the sum of the other two sides.
Let x be the length of the third side.
15-10 < x < 15+10
5 < x < 25
The answer is C.