Kaleidoscope

Make the following static figures "move".

Construct an animation
showing a rod of fixed length slides with its ends upon two fixed
perpendicular lines. What is the envelope formed by the rod? Find the point of tangency. Find the locus of a point carried by the rod. (A ladder standing on a smooth floor against a wall slides down. Along what curve does a cat sitting on the ladder move?) A wooden triangle moves on a plane so that two vertices move along two fixed perpenducluar lines. How does the third vertex move? Generalized the situation to two fixed lines not necessarily perpendicular to each other. |

Construct an animation displaying a triangle whose vertices travel along three concentric ellipses. |