The perimeter of the ABC triangle is 190cm. The AB side is 80cm, the BC side is 2 times smaller. Find the side of the speaker?

1. To solve the problem, first we find the side BC, which is 2 times smaller than AB:
80 cm / 2 = 40 cm.
2. Subtract from the perimeter of the triangle the lengths of the sides AB and BC, we get the length of the AC side:
190 cm – 80 cm – 40 cm = 190 cm – 120 cm = 70 cm.
Answer: The side of the speaker is 70 centimeters.