Constructions
Geometric Constructions ... Animated!
"Construction" in Geometry means to draw shapes, angles or lines accurately.
These constructions use only compass, straightedge (i.e. ruler) and a pencil.
This is the "pure" form of geometric construction: no numbers involved!
Learn these two first, they are used a lot:  
Line Segment Bisector  
Angle Bisector  
And it is useful to know how to do 30°, 45° and 60° angles.
We can use the angle bisector method (above) to create other angles, such as 15°, etc: 

30 Degree Angle  
45 Degree Angle  
60 Degree Angle  
Equilateral Triangle  
Points and Lines:  
Perpendicular to a Point on a Line  
Perpendicular to a Point NOT on a Line  
Parallel Line through a Point  
Same (Congruent) Angle  
Cut a line into N segments  
Circles:  
Center of a Circle  
Point to Tangents on a Circle  
Inscribe a Circle in a Triangle  
Circumscribe a Circle on a Triangle  
Circle touching 3 Points  
And for the "Master Class", a Pentagon  
Pentagon 
(Note: You can also see how to Use the Protractor, Use the Drafting Triangle and Ruler, and How to construct a Triangle With 3 Known Sides, but they are not "pure" geometric constructions.)