Electric flux through any surface is
equal to dot product of electric field and area vector.
                                   Â
EÂ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
area vector
                                                                                                                                                 Â
In this case angle b/w area vector and electric field will be
90
