Flux of electric fields

A uniform electric field of magnitude $5\sqrt{2}\times {10}^3{\text{NC}}^{-1}$‍ points toward north.

Let's imagine a square surface of area $9{\text{m}}^2$‍. The normal to this surface makes an angle of $45\mathrm{°}$‍ with the direction of the electric field.

What is the flux of the electric field through the surface?