origin is (350, 220);									// 原點(diǎn)位置
rot is 0;												// 旋轉(zhuǎn)角度為零
scale is (100, 100);									// 橫、縱坐標(biāo)比例因子
for t from 0 to 2*pi step pi/100 draw(cos(t), sin(t));	// 畫園
scale is (150, 150);									// 橫、縱坐標(biāo)比例因子
for t from 0 to 2*pi step pi/150 draw(cos(t), sin(t));	// 畫園
scale is (200, 200);									// 橫、縱坐標(biāo)比例因子
for t from 0 to 2*pi step pi/200 draw(cos(t), sin(t));	// 畫園