For now, just draw 3 walls. The angles are constants for now, with 45°.

Start values:
    w = 300
    sum_a = 0

Wall 1:
    a = 45
    start_x = 400
    start_y = 400
    center_x = start_x + (w/2) * cos(a)
    center_y = start_y + (w/2) * sin(a)
    end_x = start_x + w * cos(a)
    end_y = start_y + w * sin(a)
    sum_a = sum_a + a
	=> Draw wall at (center_x,center_y) with angle sum_a

Wall 2:
    a = 45
    start_x = end_x
    start_y = end_y
    center_x = start_x + (w/2) * cos(a)
    center_y = start_y + (w/2) * sin(a)
    end_x = start_x + w * cos(a)
    end_y = start_y + w * sin(a)
    sum_a = sum_a + a
	=> Draw wall at (center_x,center_y) with angle sum_a

Wall 3:
    a = 45
    start_x = end_x
    start_y = end_y
    center_x = start_x + (w/2) * cos(a)
    center_y = start_y + (w/2) * sin(a)
    end_x = start_x + w * cos(a)
    end_y = start_y + w * sin(a)
    sum_a = sum_a + a
	=> Draw wall at (center_x,center_y) with angle sum_a