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Name: kalman
Status: N/A
Age: N/A
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Date: Around 1995

How can you trisect an angle using a compass and straight edge? I am taking tenth grade geometry.

I do not remember anything about the proof, but trisecting an angle using compass and straightedge is not possible. Likewise, "squaring the circle" is also not possible. It may have to do with irrational (or even transcen- dental) numbers.


It depends on the angle. For example, since it is possible to construct a 30 degree angle, a right angle is trisectable. In general trisection is not possible. For a nice discussion, see Felix Klein's Famous Problems of Elementary Geometry (Chelsea 1955 and 1962 2nd ed.). Therein it states that since general trisection is related to cubic equations, and only those related to equations that may be solved using square roots are generally constructable, we cannot trisect the angle or duplicate the cube.


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