Random triples
| Subject | Object |
|---|---|
| gptkb:Ritchey–Chrétien_reflector | hyperbolic |
| gptkb:Schwarzschild_telescope | convex |
| gptkb:Dall-Kirkham_telescope | spherical |
| gptkb:Ritchey–Chrétien_telescope | hyperbolic |
| gptkb:Cassegrain_telescope | hyperboloidal |
| gptkb:Newtonian_telescope | flat |
| gptkb:Cassegrain_reflector | hyperboloid |
| gptkb:Dall-Kirkham_telescope_design | spherical |