[Solved] Positions of graphics primtives within a Graphics function

Questions
1

Hello

I expected with the code below to have the blue rectangle start at the beginning of the second segment of the line and the red rectangle at the beginning of the third segment..Their orientations are correct but not their positions. Why is it so and how is this code to be modified ?

 rectangle = Rectangle[{0, 0}, {2, 0.5}];
 Graphics[{Line[{{0, 0}, pos1 = {2 Sqrt[3], 2}, 
     pos2 = {2 Sqrt[3], 7}, {7, 7}}], Rotate[rectangle, Pi/6, {0, 0}], 
   Blue, Rotate[rectangle, Pi/2, pos1],
   Red, Rotate[rectangle, 0, pos2]}]

Mathematica V11.3
Thanks

2

Hi Jan,

The problem is that all the rectangles have the same absolute coordinates {0, 0}, {2, 0.5} so a rotation about a point is not sufficient to position them in the right place. A translation is also needed. Or create rectangles with the right coordinates and rotations e.g.

positions = {{0, 0}, {2 Sqrt[3], 2}, {2*Sqrt[3], 7}};
rotations = {Pi/6, Pi/2, 0};
colors = {Black, Blue, Red};

rectangles = Rectangle[#, # + {2, 0.5}] & /@ positions;
rotatedRectangles = 
 MapThread[{#1, Rotate[#2, #3, #4]} &, {colors, rectangles, rotations, positions}];

Graphics[{Line[Append[positions, {7, 7}]], rotatedRectangles}]

1045plot.png
1045plot.png450×464 2.94 KB

3

Nice answer. Thanks.