For the non-math readers, ruler-and-compass constructions are constructible numbers¹, which are a subset of algebraic numbers², which are a subset of computable

For the non-math readers, ruler-and-compass constructions are constructible numbers¹, which are a subset of algebraic numbers², which are a subset of computable numbers³, which are a tiny⁴ subset of complex numbers. ¹ http://mathworld.wolfram.com/ConstructibleNumber.html http://mathworld.wolfram.com/ConstructibleNumber.html ² http://mathworld.wolfram.com/AlgebraicNumber.html http://mathworld.wolfram.com/AlgebraicNumber.html ³ http://mathworld.wolfram.com/ComputableNumber.html http://mathworld.wolfram.com/ComputableNumber.html ⁴ http://mathworld.wolfram.com/MeasureZero.html http://mathworld.wolfram.com/MeasureZero.html