∴O 1 O 2 =2，O 1 A= 1，

∴O 2 A= =，

∴ The length of raw materials required for cutting the first two semicircles is 2+,

∫ Starting from the second group, the length of raw materials required for two semicircles is 2,

∴ The number of workpieces that can be cut by method 2 is 2+(20-2) ÷ 2 ≈11.392.

∫ Method 1 The number of workpieces that can be cut is 20∫2 = 10.

The ∴ cut of method 2 is more than that of method 11.392-10 =1.392 ≈1(pieces). A: Using method 2 to cut a piece of raw material is more than using method 1.