How do I create a face inside a quadrilateral/poly?

I am making a thing where you can create lines on a grid and when the first and last lines are connected, I want to have the inside filled with something graphically to show it as a "shape".

Is this possible in construct 2, using user-input as the shaping control rather than preset shapes?

At the moment it is concentrated on merely graphical representations.

Thank you

Thank you I will check it out. Looks promising