| Answer | Crossword Clue |
|---|---|
| OCTAGONS | Plane figures. |
| PENTAGONS | Plane figures. |
| NONAGONS | Plane figures. |
| ETAS | Plane figures? |
| COPILOTS | Plane figures |
| SQS | Plane figures: Abbr. |
| icositetrahedra | solid figures with twenty-four plane faces |
| planimeter | an instrument for measuring the area of plane figures |
| planimeters | PLANIMETER, an instrument for measuring the area of plane figures |
| perspectives | The relation of two figures in the same plane, such that pairs of corresponding points lie on concurrent lines, and corresponding lines meet in collinear points |
