Each of the following construction name provides a link to a GSP file which has a script tool for the construction. Below each of them is an applet that show how your construction will look at the end of using the GSP script tool.
Centroid
Orthocenter
Circumcenter
Circumcircle
Incenter
Incircle
Medial Triangle
Orthocenter, Mid-Segment Triangle
Orthic Triangle
Pedal Triangle
Center of Nine Point Circle
Nine Point Circle
Trisecting a Line Segment
Equilateral Triangle (given a side)
Square (given a side)
Isosceles Triangle (given base and altitude)
Triangle Centers (H, G, C, and I)
Triangle Centers with Euler Line
Locus of Vertex of a Fixed Angle that Subtends a Fixed Segment
Divide a Segment AB into Two Parts that Form a Golden Ratio
Pentagon (given a radius)
Pentagon (given a side)
Hexagon (given a side)
Octagon (given a side)
Tangent Circles