1, and the other side = 3a+2b+(a-b) = 4a-b.

Circumference = 2× [(3a+2b)+(4a-b)] = 2× (7a+b) =14a+2b

2. The second side length = 3a+2b+(b-1) = 3a+3b-1.

The third side length = 3a+3b-1+2 = 3a+3b+1.

Circumference = (3a+2b)+(3a+3b-1)+(3a+3b+1) = 9a+8b

3. Number of people in the second workshop =4/5x-30

The second workshop transferred 10 people to the first workshop. At this time,

Number of people in the second workshop =4/5x-30- 10=4/5x-40.

Number of people in the first workshop =x+ 10

a * * * =(4/5x-40)+(x+ 10)= 9/5x-30。