Originally Posted by
smd4
Listen, you clearly don't know what "perpendicular" means, and maybe you don't even know what "90 Degrees" means. Personally, I think the wedge of the cotter is what's confusing you. But I digress. It's a waste of time for me trying to explain it to you. Good luck in your 3D world.
Apparently. You explained nothing. But you did waste time writing posts.
In elementary geometry, two geometric objects are perpendicular if their intersection forms right angles (angles that are 90 degrees or π/2 radians wide) at the point of intersection called a foot. The condition of perpendicularity may be represented graphically using the perpendicular symbol, ⟂. Perpendicular intersections can happen between two lines (or two line segments), between a line and a plane, and between two planes.
https://en.wikipedia.org/wiki/Perpendicular
I still wouldn't describe a chord as perpendicular unless it also ran through the center of the circle. And the cotter bolts I'm familiar with do not go through the center of the spindle/axle.