According to my understanding:
- two orthogonal forces aren't related and two orthogonal vectors don't affect each other
- the force of static friction $F_s$ depends on the normal force $F_n$, so $F_s = F_n\cdot c$$$F_s = \mu_s F_n$$ ($c$$\mu_s$ being the static friction coefficient).
If these two are correct, how can the force of static friction, determined by a force normal to the surface, be directed tangential to the surface and orthogonal to the normal force?