По запросу: "drawing a horizontal line from the upper left corner to the lower right corner" найдено 144 иконки.

border-right
i
right_line
image/svg+xml 2016 Timothée Giet
line-chart-outline-alerted
Gestures
carousel--horizontal
Swap items (horizontally)
https://www.svgrepo.com/show/529300/video-frame-play-horizontal.svg
quote-right
right-arrow Created with Sketch.
prime
Arrow Left
LImit-left Created with Sketch.