Pick any point on a conic section, and draw a series of right angles having this point as their vertices. Then the line segments connecting the rays of the right angles where they intersect the conic section concur in a point , as illustrated above.
More things to try:
Weisstein, Eric W. "Frégier's Theorem." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/FregiersTheorem.html
on a conic section, and draw a series of right
angles having this point as their vertices. Then the line segments connecting
the rays of the right angles where they intersect
the conic section concur in a point 
, as illustrated above.
