Answer:

Explanation:
The electric flux through a certain surface is given by (for a uniform field):

where:
E is the magnitude of the electric field
A is the area of the surface
is the angle between the direction of the field and of the normal to the surface
In this problem, we have:
is the electric field
L = 2.0 m is the side of the sheet, so the area is

, since the electric field is perpendicular to the surface
Therefore, the electric flux is
