Robuta

https://ggplot2.tidyverse.org/reference/geom_abline.html Reference lines: horizontal, vertical, and diagonal — geom_abline • ggplot2 These geoms add reference lines (sometimes called rules) to a plot, either horizontal, vertical, or diagonal (specified by slope and intercept). These are... reference lines horizontal vertical diagonal geom https://www.mathopenref.com/coordperpendicular.html Perpendicular lines. (Coordinate Geometry) - Math Open Reference How to determine if lines are perpendicular in coordinate geometry math open reference perpendicular lines coordinate geometry