Lost in Space
Why is it smaller? After each step, the turtle turns twice as much as the one on the previous page (RIGHT 2 instead of RIGHT 1). So it only needs to take half as many steps to get around. The resulting circle has half the circumference and half the radius of the one on the previous page. Try other numbers. For example, what happens with FORWARD 2 RIGHT 2? Some readers might be bothered by a "trick" in our examples. The turtles aren't really making circles; they are making regular polygons with a large number of sides. The FORWARD 2 RIGHT 2 command draws a polygon with 180 sides; the FORWARD 1 RIGHT 1 command draws a polygon with 360 sides. What if you kept reducing the step size and turn size? You would get polygons with more and more sides, looking more and more like circles. In fact, by reducing the step size and turn size, you can get as close to making a real circle as you want. Go to the next page or the previous page or the contents page. Mitchel Resnick and Brian Silverman Epistemology and Learning Group MIT Media Laboratory Last modified: 2/4/96 |