Problem
1. Write a routine to implement point inversion, for any specified circle and any given point position.
2. Devise a set of substitution rules for altering the shape of an equilateral triangle.
3. Write a program to display the stages in the conversion of an equilateral triangle into another shape, given a set of geometric-substitution rules.
4. Write a program to model an exploding firecracker in the xy plane using a particle system.
5. Devise an algorithm for modeling a rectangle as a nonrigid body, using identical springs for the four sides of the rectangle.