Any new shapes drawn after the translate function appears using the offset; so in this case, the rect function actually creates a square at 100, 100, 150, 150, as shown in Figure 1, cell a.
translate函数之后绘制的任何形状都会加上这个偏移量；所以在这里，rect函数实际上在坐标100,100,150,150上创建一个正方形，如图1的单元格a所示。