Shadow cast

Hello,

 I am a new rhino and grasshopper user.( it is better when I see how it is done as hard to understand the grasshopper ''language'' yet)

I hope some of you can help me.

I am trying to achieve a equilateral triangle shadow castted by combination of triangular forms can be rotated or be distorted triangular shapes( e.g. half triangle. 1/3 part of triangle) but it has to cast the shadow of equilateral triangle. May you please suggest on how to achieve it?as spend too much time to do it manually and still doesnt work.  I shared the rhino and grasshopper script below. Thank you for help.

Best, Ana