<s id="A18-1.17.01">[17] Also with the solid figures, the regular as well as the irregular, we have to imagine the transfer in a similar way - only with a sphere taking the place of the circle, inside or outside of which we construct the congruent figures.</s>
<s id="A18-1.17.02">Thus we assume similarly situated points on the sphere and draw, starting from them towards other points situated inside the figure, lines and extend them.</s>
<s id="A18-1.17.03">When we have done this, a solid figure forms from these lines, which is equal and similar to the one first assumed.</s>