A 51 cm x 38 cm rectangle lies in the xz-place what is the

Question

Compute each part of given problem:

Problem: A 5.1 cm x 3.8 cm rectangle lies in the xz-place.

Part A: What is the electric flux through the rectangle if E = (100i+40k)N/C?

Part B: What is the electric flux through the rectangle if E = (100i+40j)N/C?

Please show all intermediate steps and formulas for above problem.