Across
- 5. Rise over run, line’s steepness
- 9. Fence around the shape
- 11. Straight and endless, no bends allowed
- 12. Blunt angle, larger than a right angle
- 14. Balanced halves in a mirror image
- 16. Diamond shape in disguise
- 18. Four-sided polygon’s formal name
- 20. Half a diameter, from center
- 21. Perfectly round three-dimensional buddy
- 23. Stop if you see this shape!
- 26. Exactly the same size and shape
- 28. Perimeter's circular cousin
- 30. Round fellow with no corners
- 31. Flat patterns fold up into 3D shapes
- 32. Two sides, same but not three
- 33. Lines that never seem to meet
- 34. Honeycomb shape and more
- 36. Twice the radius, straight through
- 38. segment — Line with definite ends
- 40. Ten sides, often missed in counting
- 41. Equal sides, equal angles too
- 42. Theorem involving squares and triangles
- 43. Grid point, probably on the plane
Down
- 1. Slice of a circle pie
- 2. No sides equal, no angles equal either
- 3. At a right angle, standing tall
- 4. Folds the angle in half, perfectly
- 6. Corner point where edges meet
- 7. Slanted box, one pair of parallel sides
- 8. The longest side of a right triangle
- 10. Surface measure, often in square units
- 13. Same shape, different size (maybe)
- 15. Three sides, three angles to count
- 17. Sharp, but less than 90°
- 19. One pair of parallel sides on display
- 22. Space inside a 3D shape
- 24. Line that just touches a curve
- 25. Flat surface on a solid shape
- 27. Shape with a uniform cross section
- 29. Four right angles, opposite sides match
- 30. Can with two matching ends
- 33. Many sides, all connected
- 35. This can be right or obtuse
- 37. Triangle with equal sides all around
- 39. Two angles that add to 90°