Electric Field - stepwise consideration of Gauss's Law

Consider stepwise application of Gauss's law in the following three cases.
 

System	Infinite line of charge	Infinite plane of charge	Uniformly charged solid sphere
Figure
Identify the symmetry	Cylindrical	Planar	Spherical
Determine the direction of
Divide the space into different regions	r > 0	z > 0 and z < 0	r  a and r  a
Choose Gaussian surface
Calculate electric surface	E = E(2rl)	E = EA + EA = 2EA	E = = E(4r2)
Calculate enclosed charge qin	qenc =  l	qenc =  A
Apply Gauss's law E = qin /   to find E