Merry-Go-Round-Triangle
The YELLOW dots form a triangle with blue, green and purple sides. Starting from the ORANGE point a line is drawn parallel to the purple side of the triangle, followed by a green lie parallel to the green side of the triangle, etc. This process is continued.
You can make any shape triangle you like by dragging yellow dots. You can position the orange dot wherever you like on the (green) leg of the triangle.
Why does the dotted pathway always close?
What questions could/would you ask of your students based on this applet?