Question

The sum of lengths of any two sides of a triangle must be greater than the length of the third side. What are the possible values of X for this triangle?

One side is (3x) cm the other is (x + 5) cm and the last one is 40 cm

Answer 1

35/4 < x < 45/2

Explanation:

3x + x + 5 > 40

4x > 35

x > 35/4

3x + 40 > x + 5

2x > -35

x > -35/2

x + 5 + 40 > 3x

45 > 2x

45/2 > x

x < 45/2

x has to be larger than -35/2 and larger than 35/4. so in combination, the larger number wins as lower limit.

and x has to be lower than 45/2.

so, overall the valid values for x are in the interval

35/4 < x < 45/2