pascal law states that the pressure exerted is same at all directions if the fluid is at rest ...
let us take a prism shaped object abc-def inside a container with fluid. the fluid exerts a pressure on the surface of object (i.e pa,pb,pc) of area corresponding to the forces fa ,fb ,fc on the surfaces of BECF,ADFC,ADEB. let the areas corresponding to the forces be Aa,Ab,Ac. Gravity is neglected becauze the object is very small.
Fb sin (theta) = Fc ( by equilibrium)
Absin (theta)= Ac
Fb cos (theta) = Fa
Ab cos (theta) = Aa
therefore , Fb/Ab= Fc/Ac=Fa/Aa
i.e Pb=Pc=Pa
hence proved that the pressures are equal in all directions
THE FIGURE IS GIVEN IN TEXTBOOK PAGE NO-- 248 (2 PART )
Ab