the.com/perpendicular
Two lines meeting at a perfect right angle, agreeing on nothing but ninety degrees.
means Describes lines, surfaces, or directions that intersect at a 90-degree angle to each other.
from From Latin perpendiculum, a plumb line — the weighted string masons hung to find true vertical, gravity itself drawing the standard.
Plumb rootsNamed for the lead weight that defines vertical.
SymbolMathematicians mark it with a tidy upside-down T.
ArchitectureA Gothic English style obsessed with soaring vertical lines.