# 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 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.)