1.a stands for pi [unit length 1 bit diameter d circumference is d* pi, so OA is pi]

2. 1) 22,500 yuan per ton of raw materials->; 22.5 yuan per kilogram

The raw material is100m18kg->; Raw material cost: 18*22.5

100m Power consumption: 80*0.5

100m Payable Labor Fee: 100*0.38=38 yuan.

100m dyeing setting:100 *1.16 =116 yuan.

Because it has shrunk by 5%, the cost of weaving 95m cloth is18 * 22.5+80 * 0.5+38+116.

Per meter (18 * 22.5+80 * 0.5+38+116)/95 = 599/95 yuan.

2)30% profit (599/95) * (1+30%)