Constructions
Geometric Constructions ... Animated!
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"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! |
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| Learn these two first, they are used a lot: | |
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Line Bisector |
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Angle Bisector |
| And it is useful to know how to do 30°, 45° and 60° angles. You can use the angle bisector method (above) to create other angles, such as 15°, etc: | |
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30 Degree Angle |
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45 Degree Angle |
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60 Degree Angle |
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Equilateral Triangle |
| Points and Lines: | |
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Perpendicular to a Point on a Line |
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Perpendicular to a Point NOT on a Line |
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Parallel Line through a Point |
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Same (Congruent) Angle |
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Cut a line into N segments |
| Circles: | |
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Center of a Circle |
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Point to Tangents on a Circle |
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Inscribe a Circle in a Triangle |
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Circumscribe a Circle on a Triangle |
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Circle touching 3 Points |
| And for the "Master Class", a Pentagon | |
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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.)