Here are some GSP tools I have created.
Orthocenter, Mid-Segment Triangle
Equilateral Triangle - given a side
Isosceles Triangle - given base and altitude
Square - given a side
Hexagon - given a side
Octagon - given a side
Circle Tangent to Two Circles - version 1
Circle Tangent to Two Circles - version 2
Circle Tangent to Two Circles - version 3
Circle Tangent to Two Circles - version 4
Circle Tangent to Two Circles - version 5
Circles Tangent to Two Circles - version 6 - draws both tangent circles