There is a square $ABCD$, line $EF$ and point $G$ on a plane. Can you construct the foot of perpendicular to line $EF$ through point $G$, using only a straightedge (in traditional Euclidean constructions)? Is there any construction shorter than mine?
I'd appreciate it if you posted a construction or provided any kinds of reference.
The following construction has complexity 30.
Construct 3x3 grid.
Construct the parallel line and the perpendicular line of line EF through point L.
Construct the perpendicular line of line EF through G by making c symmetric to G about line LZ.
GWLZa GXLZb WbXac EFGcd

And here is the result. It's really complex.
- The complexity of a construction can be described by the quantity of points.
XYZUVis short for "creating point $V$ which is the intersection of line $XY$ and $ZU$".- Notice that points can be in either capital and lowercase letters.





