If two lines force intersect at one point. What does it mean?

Four charges of $+6\times {10}^{-8}C$ each are placed at the corners of a square whose sides are $3 \mathrm{cm}$, each. Calculate the resultant force on each charge and show direction in a diagram drawn to scale.

The electric field in a region is given by  $E=5.0 \mathrm{kN}/\mathrm{C}$. Calculate the electric flux through a square of side $10.0 \mathrm{cm}$ in the following case:

When the square is along the $XY$ plane.