To construct a rectilinear angle equal to a given rectilinear angle at a (given) point on a given straight line. * Let $AB$ be the given straight line, $A$ the (given) point on it, and $DCE$ the given rectilinear angle. * So it is required to construct a rectilinear angle equal to the given rectilinear angle $DCE$ at the (given) point $A$ on the given straight line $AB$.
It is possible to construct an angle $\angle{FAG}$ equal to an arbitrary angle $\angle{CDE}$ on an endpoint of a given segment $\overline{AB}.$
Proofs: 1
Proofs: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
Sections: 19