1. GEOMETRY

2. POINT
Has no size, only location A

3. LINE
Continues without end in opposite directions. You can name a line by using two points on the line. A B AB

4. PLANE
A flat surface that extends indefinitely in four directions.

5. PARALLEL LINES
Lines in the same plane that do not intersect.

6. ANGLE
is made up of two lines with a common endpoint called the vertex. O
VERTEX M P
<OMP or <PMO

7. RIGHT ANGLE
Measures exactly 90° W X Z
<WXZ or <ZWX

8. OBTUSE ANGLE Measures greater than 90° and less than 180° U K T
<UTK or <KTU

9. STRAIGHT ANGLE
Measures exactly 180° C R B
<CBR or < RBC

10. PERPENDICULAR
Lines that intersect to form right angles.

11. COMPLEMENTARY ANGLES Two angles, the sum of whose measures is 90°. R S
<RTS and <STU are complementary angles T U

12. SUPPLEMENTARY ANGLES Two angles, the sum of whose measures is 180 I GD F
<DGI and <IGF are supplementary angles

13. TRANSVERSE LINES Intersect a pair of parallel lines.
<s 1 & 2 and <s 7 & 8 are outside the parallel lines. They are exterior angles. 1 2 7 8

14. <s 3,4,5, and 6 are inside the parallel lines
<s 3,4,5, and 6 are inside the parallel lines. They are called interior angles. 3 4 5 6

15. CONGRUENT ANGLES
Angles that have the same measure.

16. ACUTE TRIANGLE
A triangle with three acute angles.

17. OBTUSE TRIANGLE
A triangle with one obtuse angle.

18. RIGHT TRIANGLE
A triangle that has one right angle.

19. EQUILATERAL TRIANGLE
A triangle with three congruent sides and three congruent angles.

20. ISOSCELES TRIANGLE
A triangle that has two congruent sides.

21. SCALENE TRIANGLE
A triangle with no congruent sides.

22. POLYGON
A closed shape formed by line segments that do not cross.

23. CONVEX POLYGON
A rubber band can fit tightly around this figure.

24. PARALLELOGRAM
A quadrilateral with both pairs of opposite sides parallel.

25. RECTANGLE
A parallelogram with four right angles.

26. RHOMBUS
A parallelogram with four congruent sides.

27. SQUARE
A rectangle with four congruent sides.

28. TRAPEZIUM
A quadrilateral with exactly one pair of parallel sides.