Visualizing Liquid Pressure: A Diagrammatic Guide

[Pranav Jha]

The forces of a liquid pressing against a surface add up to a net force that is perpendicular to the surface.

I cannot visualize this. Could someone help me out diagrammatically here?

 

[Pranav Jha]

The diagram given in my book is a triangle placed in water and three perpendicular force vectors are shown but i don't why the other non-perpendicular vectors haven't been shown. The book mentions that the non-perpendicular components cancel each other but
again i cannot picture them canceling each other, duh!