Across
- 6. a plane figure with three straight sides and three angles
- 7. a straight line joining two opposite corners of a square, rectangle, or other straight-sided shape
- 8. a four-sided figure
- 10. a plane figure with five straight sides and five angles
- 13. each of the pairs of opposite angles made by two intersecting lines
- 17. a plane figure with at least three straight sides and angles, and typically five or more
- 19. Lines that are at right angles (90°) to each other
- 22. a triangle that has 3 acute angles
- 23. A line with a start point but no end point
- 24. a parallelogram with opposite equal acute angles, opposite equal obtuse angles, and four equal sides
- 25. an angle of 180°
- 27. an angle more than 180° but less than 360°
- 28. part of a line that is bounded by two distinct end points
- 30. identical in form
- 31. a triangle that has two sides of equal length
- 33. a plane figure with nine straight sides and nine angles
- 34. An angle that measures more than 90 degrees but less than 180 degrees
- 36. either of two angles whose sum is 90°
- 37. triangle a triangle with a right angle
- 38. a plane figure with six straight sides and angles
- 41. two angles that share a common vertex and common side
- 42. a straight line passing from side to side through the center of a body or figure, especially a circle or sphere
Down
- 1. either of two angles whose sum is 180°
- 2. the exact middle point
- 3. an angle of 90°
- 4. a straight path that is endless in both directions
- 5. all angles are equal and all sides are equal
- 9. a plane figure with four equal straight sides and four right angles
- 11. 1. All pairs of corresponding angles are congruent. 2. The ratios of the measures of corresponding sides are equal. The symbol “∼” means “similar to”
- 12. the space between two intersecting lines or surfaces
- 14. A triangle with all three sides of equal length
- 15. the size of a two dimensional figure
- 16. a triangle in which one of the angles is an obtuse angle
- 17. an instrument for measuring angles, typically in the form of a flat semicircle marked with degrees along the curved edge
- 18. an exact position or location on a plane surface
- 19. a four-sided plane rectilinear figure with opposite sides parallel
- 20. two lines in a plane that do not intersect or touch at any point
- 21. a plane figure with four straight sides and four right angles, especially one with unequal adjacent sides, in contrast to a square
- 26. an angle that is greater than 0 degrees but less than 90 degrees
- 29. the enclosing boundary of a curved geometric figure, especially a circle
- 30. a round plane figure whose boundary consists of points equidistant from a fixed point
- 32. a triangle that has three unequal sides
- 35. a plane figure with eight straight sides and eight angles
- 39. an instrument for drawing circles and arcs and measuring distances between points, consisting of two arms linked by a movable joint, one arm ending in a point and the other usually carrying a pencil or pen
- 40. a quadrilateral with only one pair of parallel sides