The side of the triangle is 140 cm, making up 7/20 of the perimeter of the triangle. What is the perimeter of a triangle?

We denote the perimeter of the triangle as the unknown value of x.
The number x will correspond to 1 just like the known side length, namely 140 cm is 7/20.
As a result, we get the following proportion:
140/7/20 = 140 * 20/7 = 20 * 20 = 400 cm.
Answer: The perimeter of the triangle is 400 cm.

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