Question

Select all the correct answers.

You're given two side lengths of 6 centimeters and 9 centimeters. Which measurement can you use for the length of the third side to construct a valid triangle?
3 centimeters
10 centimeters
12 centimeters
14 centimeters
18 centimeters

Answer 1

If the third side is longer than 15 cm, then the 6 and the 9 together
can't reach its ends.

-- If the third side is shorter than 3 cm, then IT can't reach the ends
of the 6 and the 9.

-- So the third side must be longer than 3cm AND shorter than 15 cm.

3cm < S < 15cm