GEOM Vocab Quiz 1

1. Geometry

The branch of mathematics that is the study of shapes, lines, angles, and space.

2. Point

Indicates a location.

3. Line

A straight path extending infinitely in opposite directions.

4. Line segment

Part of a line with two endpoints.

5. Ray

Part of a line that starts at a point and extends infinitely in one direction.

6. Vertex

The point of intersection of two or more line segments, rays, or lines.

7. Angle

Formed by two rays with the same endpoint, the vertex.

8. Triangle

Shape with three sides and three vertices.

9. Parallel lines

Lines that are always the same distance apart and never meet.

10. Perpendicular lines

Lines that intersect to form four right angles.

11. Collinear

Points on the same line.

12. Plane

A flat surface that extends infinitely in all directions.

13. Coplanar

Points lie on the same plane.

14. Intersect

To pass through or lie across each other.

15. Postulate

A statement that is accepted as fact, without proof.

16. Theorem

A statement that has been proven to be true using other theorems, definitions, or postulates.

17. Segment-Addition Postulate

If B is a point on line segment AC, then AB + BC = AC.

18. Congruent

Have the same length or measure.

19. Tick Marks

Used to show that line segments are congruent.

20. Midpoint

The halfway point of a line segment, it divides the line segment into two congruent segments.

21. Segment Bisector

A line, ray, segment, or plane that passes through a segment at its midpoint.

22. Interior

Space or points inside of an angle.

23. Exterior

Space or points outside of an angle.

24. Right Angle

Angle that measures exactly 90 degrees.

25. Acute Angle

Angle that measures greater than 0 but less than 90 degrees.

26. Obtuse Angle

Angle that measures greater than 90 but less than 180 degrees.

27. Straight Angle

Angle that measures exactly 180 degrees.

28. Adjacent Angle

Angles that lie in the same plane, have a common vertex, share a common side, and have no common interior points.

29. Non-adjacent Angle

Angles that do not have a vertex or a side in common.

30. Angle Addition Postulate

If point R is in the interior of angle QPS, then the measure of angle QPR + the measure of RPS = the measure of angle QPS.

31. Angle Marks

Show that angles are congruent.

32. Angle Pairs

Angles that are related to each other by their measures or orientations.

33. Vertical Angles

Angles that are nonadjacent and opposite each other, formed when two lines intersect and share the same vertex.

34. Complementary Angles

Two angles whose sum is 90 degrees.

35. Supplementary Angles

Two angles whose sum is 180 degrees.

36. Linear pairs

Two angles that are adjacent and supplementary.

37. Angle Bisector

A ray that divides an angle into two congruent angles.

38. Perpendicular Bisector

A line, ray, or line segment that divides a line segment into two congruent segments and forms four right angles with it.

39. Construct

To use a compass and a straightedge to draw accurate shapes, angles, and lines.

40. Compass

Mechanical device with a needle, hinge, and pencil.