Across
- 2. any two angles whose sum is 180°
- 3. a closed plane figure formed by three or more line segments
- 6. a line, ray, or segment that intersects a segment at its midpoint
- 8. used to find the distance between two points
- 13. two lines that intersect at a right angle
- 14. two segments with the same length
- 16. part of a line that consists of one endpoint and extends infinitely in one direction
- 21. formed by two rays with a common endpoint
- 26. used to find the midpoint between two points
- 28. a type of polygon that has at least one angle that measures greater than 180°
- 30. the amount of space the polygon encloses
- 31. a ray that divides an angle into two congruent angles
- 33. if D is the interior of ∠ABC, then m∠ABD + m∠DBC = m∠ABC
- 35. represented by a dot; has no size or shape
- 36. two planes intersect at a _____________
- 37. a flat surface made up of points
Down
- 1. a line, segment, or ray perpendicular to a segment at its midpoint
- 4. made up of points; goes on infinitely
- 5. a rule that is accepted without proof
- 7. if three points A, B, and C are collinear and point B is between points A and C, then AB + BC = AC
- 9. any two angles whose sum is 90°
- 10. a point that divides a segment into two congruent segments
- 11. an angle measuring less than 90°
- 12. part of a line that consists of two endpoints and all the points between them
- 15. a polygon with four sides
- 17. an angle measuring 180°
- 18. two angles across from each other on intersecting lines; always congruent
- 19. an angle measuring more than 90° and less than 180°
- 20. two angles with the same measurement
- 22. a rule that can be proved
- 23. the sum of the lengths of a polygon’s sides
- 24. two angles that are next to each other and share a common side
- 25. two lines intersect at a _____________
- 27. an angle measuring 90°
- 29. a polygon with ten sides
- 32. two angles that are adjacent and supplementary; form a straight line
- 34. have the same endpoint and extend indefinitely in opposite directions