data-ad-format="horizontal">



 

Constructing a 90° (right) angle

This is the step-by-step, printable version. If you PRINT this page, any ads will not be printed.

See also the animated version.

After doing this Your work should look like this
Start with a ray with endpoint C. The right angle will have C as its vertex.
1.  Mark a point, not on the given line, about 6 cm in from C. Its exact location is not important. Label it D.
2.  Set the compasses on point D and set their width to the endpoint C .
3.  Draw an arc that crosses the given line and extends over and above the endpoint C. (If you prefer, draw a complete circle.)
4.  Draw a diameter through D from the point where the arc crosses the given line, creating points B and A.
5.  Draw a line from C to the endpoint A of the diameter line
6.  Done. The angle ACB is a right angle (90 deg).  
While you are here..

... I have a small favor to ask. Over the years we have used advertising to support the site so it can remain free for everyone. However, advertising revenue is falling and I have always hated the ads. So, would you go to Patreon and become a patron of the site? When we reach the goal I will remove all advertising from the site.

It only takes a minute and any amount would be greatly appreciated. Thank you for considering it!   – John Page

Become a patron of the site at   patreon.com/mathopenref

Other constructions pages on this site

Lines

Angles

Triangles

Right triangles

Triangle Centers

Circles, Arcs and Ellipses

Polygons

Non-Euclidean constructions