| Answer | Crossword Clue |
|---|---|
| era | a fixed point in time from which a series of years is reckoned |
| inversion | A transformation in which each point of a given figure is replaced by another point on the same straight line from a fixed point, esp. in such a way that the product of the distances of the two points from the center of inversion is constant |
| inversions | A transformation in which each point of a given figure is replaced by another point on the same straight line from a fixed point, esp. in such a way that the product of the distances of the two points from the center of inversion is constant |
