Drawing like a pro - Homework #7 / We try very complex shadows.

Hi friends!
I am reading @jorgevandeperre's homework
I understood a lot.

Today I'm going to try very complex shadows.
This is what happened to @setf1 when trying to draw shadows for somewhat more complex figures.

This is @jorgevandeperre's solution to draw the shadows in this case.
Drawing like a pro - 67, Comenting on your drawing (part 1) -Lights and Shadows (Power up 100%)

I did this assignment because I was allowed to try @setf1's assignment.

I think it's wrong that the shadow doesn't go to the vanishing point in my painting.
I would appreciate it if @jorgevandeperre could point out the problems with my painting.

In my first picture, the vertical line, the horizontal line, and the diagonal line were slightly error-prone, and the bright floor was narrowed in the center.

And this is the shape of the natural shadow that I think of in the content of the teacher's education.
The shape of the shadow on the wall is a little strange, but I don't know if it's right?

Is it just a coincidence that the line connecting A and B became a straight line with the red line?