A key search term is *geometric tomography*.
<hr />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
[![Xrays][1]][1]
<br />
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 
<sup>
Two shapes with the same parallel X-rays.
</sup>
<hr />


  [1]: https://i.sstatic.net/0qPjh.jpg