| Answer | Crossword Clue |
|---|---|
| fillet | concave junction formed where two surfaces meet (as at an angle) |
| piend | the line, ridge, or hip formed by the meeting of two surfaces at an exterior angle |
| piends | the line, ridge, or hip formed by the meeting of two surfaces at an exterior angle |
| arris | the line, ridge, or hip formed by the meeting of two surfaces at an exterior angle |
| grooves | An indentation where two planes of rock meet at an angle of more than 120░ |
| dihedrals | A place where two planes of rock meet at an angle of between 60░ and 120░ |
