A triangle has one side of length 29 units and another of length 40 units. Determine the range in which the length of the third side must lie.

A. -11< x < 69

B. 11≤ x ≤ 69

C. 11< x < 69

D. -11≤ x ≤ 69

The answer is C.

Sum of two sides of a triangle is greater than third side

29 + 40 > x where x=length of the third side

Diffrence of two sides < length of third side

40 - 29 < x

29 + 40 > x > 40 - 29

69 > x > 11 or 11 < x < 69