The perimeter of a triangle is 160 cm. If two of the sides are 40 cm and 50 cm, calculate the length of the third side? Let's think first. Chain of thought:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
To get the perimeter, you add all the sides o the triangles, so the first two sides add up to 40 + 50 = 90 cm. If the perimeter of the triangle is 160, the remaining side is 160 - 90 = 70 cm.
Therefore, the answer is 70.