![](https://www.mathopenref.com/images/constructions/constorthocenter/ortho1.gif)
How to construct the orthocenter of a triangle with compass and straightedge or ruler. The orthocenter is the point where all three altitudes of the triangle intersect. An altitude is a line which passes through a vertex of the triangle and is perpendicular to the opposite side. A Euclidean construction
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How to Construct the Orthocenter of a Triangle, Geometry
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Printable instructions for finding the orthocenter of a triangle with compass and straightedge or ruler
![](https://upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Incircle_and_Excircles.svg/300px-Incircle_and_Excircles.svg.png)
Incircle and excircles - Wikipedia
![](https://www.onlinemath4all.com/images/constructionofperpendicular8.png)
Construction of Orthocenter of a Triangle
![](https://www.mathopenref.com/images/constructions/constorthocenter/step3.png)
Printable instructions for finding the orthocenter of a triangle with compass and straightedge or ruler
![](https://i.ytimg.com/vi/pjoU0mzg7IE/sddefault.jpg)
5.4 Orthocenter Compass Construction / acute triangle
![](https://qph.cf2.quoracdn.net/main-qimg-ef58ba2b34e8138acac4b129e5f30963.webp)
Does an obtuse angle triangle have an orthocenter? - Quora
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Solving olympiad geometry without human demonstrations
![](https://www.mathopenref.com/images/constructions/constorthocenter/step1.png)
Printable instructions for finding the orthocenter of a triangle with compass and straightedge or ruler
Incenter - Wikipedia
Orthocenter Calculator, Definition
![](https://www.mdpi.com/mathematics/mathematics-10-01381/article_deploy/html/images/mathematics-10-01381-g001-550.jpg)
Mathematics, Free Full-Text
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How to construct an isosceles triangle given base and one side - Math Open Reference