Below is an instruction that describes a task. Write a response that appropriately completes the request in Swahili. Please answer in Swahili.

### Instruction:
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?

### Response:
 Ili kupata umbo wa pembetatu, unahitaji kuongeza pande zote, hivyo 40 + 50 + upande mwingine = 160
Ikiwa pande mbili zina jumla ya 160, basi upande mwingine ni 160-40-50 = <<160-40-50=70>>70 cm.