Constructions

Geometric Constructions ... Animated!

Compass

"Construction" in Geometry means to draw shapes, angles or lines accurately.

These constructions use only compass, straightedge (a ruler, but not using the numbers) and a pencil.

pencil

This is the "pure" form of geometric construction: no numbers involved!

Basics

Learn these two first, they are used a lot:

Points and Lines

Angles

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.

Triangle Basics

Triangle Centers

Circle Basics

Circles and Tangents

Polygons

And for the "Master Class":

 

 

(Note: You can also see how to Use the Drafting Triangle and Ruler, Use the Protractor, and How to construct a Triangle With 3 Known Sides, but they are not "pure" geometric constructions.)