What is the number of 360 divided into 1:2:3:4:5:6:7:8:9? It's not divided equally, it's distributed according to the above proportion
8 16 24 32 40 48 56 64 72
As shown in Figure 8-3, it is obtained by folding △ ABC of figure 8-1 along de. if ∠ a = 30 °, then x + y = 360 - (∠ B + ∠ C + ∠ 1 = ∠ 2) is equal to 360 °-
360°-300°=60°