Constructing 75° 105° 120° 135° 150° angles and more
On other pages there are instructions for constructing angles of 30°, 45°, 60° and 90°.
By combining them you can construct other angles.
For example, by first constructing a 30° angle and then a 45° angle, you will get a 75° angle.
The table below shows angles that can be obtained by combining simpler ones in various ways:
Furthermore, by combining three angles many more can be constructed.
You can subtract them too
By constructing an angle "inside" another you can effectively subtract them.
So if you started with a 70° angle and constructed a 45° angle inside it sharing a side, the result would be a 25° angle.
The basic constructions are described on these pages:
Constructions pages on this site
Circles, Arcs and Ellipses
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