Download LIST # 2: Geometry Vocabulary Words:

LIST # 2: Geometry Vocabulary Words:
APPROPRIATE FOR a) Academic Geometry b) Geometry c) Honors Geometry
1. Line segment: a measurable part of a line that consists of two points, called
endpoints, and all of the points between them
2. Congruent: having the same measure
3. Theorem: a statement that can be proven to be true
4. Postulate: statement accepted as true without proof
5. Protractor: a device for measuring angles
6. Transversal: a line that intersects two or more lines at different points
7. Vertical Angles: two nonadjacent congruent angles formed by two intersecting
lines
8. Complementary Angles: two angles whose measures have a sum of 90
9. Supplementary Angles: two angles whose measures have a sum of 180
10. Perpendicular Lines: lines that form right angles
11. Parallel Lines: coplanar lines that do not intersect
12. Similar Figures: figures whose corresponding angles are congruent but
corresponding sides are in proportion
13. Reflection: a transformation representing a flip of the figure over a point, line or
plane
14. Rotation: a transformation that turns every point of a reimage thru a specified
angle and direction about a fixed point, called the center of rotation
15. Scale Factor: the ratios of the lengths of two corresponding sides of two similar
polygons or two similar solids
16. Dilation: a transformation determined by a center point P and scale factor
17. Surface Area: the sum of the areas of all faces and side surfaces of a three
dimensional figure
18. Circle: the locus of points in a plane equidistant from a given point called the
center of the circle
19. Radius: any segment connecting the center of a circle/sphere to a point on the
circle/sphere
20. Central Angle: an angle that intersects the circle at two points and has its vertex
at the center of the circle
21. Pi: an irrational number represented by the ratio of the circumference of the
circle and the diameter of the circle
22. Arc: a part of a circle that is defined by two endpoints
23. Chord: a segment whose endpoints are on the circle