Mark a point on a side of a triangle and draw the perpendiculars from the point to the two other sides. The line between the feet of these two perpendiculars is called the pedal line.
Pedal Line
See also
Antipedal Line, Pedal Triangle, Simson LineExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Pedal Line." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/PedalLine.html