Across
- 4. - two lines that never intersect and remain the same distance apart.
- 7. - the distance between one crest of a wave and the next.
- 8. - a straight one-dimensional figure with no thickness.
- 10. - the distance from a place of rest to the crest of a wave.
- 12. - the top part of the wave.
- 16. - lines that cross at one point.
- 17. - two lines that intersect at a 90-degree angle.
- 18. - an energy wave that is shorter than a radio wave.
Down
- 1. - an angle greater than 90 degrees but less than 180 degrees.
- 2. - the distance east or west of the prime meridian.
- 3. - half of a sphere, especially one of the Earth's halves.
- 5. - an imaginary line around the middle of the Earth.
- 6. - the space between two intersecting lines measured in degrees.
- 9. - an exact location in space.
- 11. - the distance north or south of the equator.
- 13. - a radio wave sent or received.
- 14. - a unit used to measure sound.
- 15. - matter in which something is carried.