| A | B |
|---|
| geometry | study of shapes, their parts, and their properties |
| point | no size - no shape |
| line | collection of points - extends forever |
| plane | never ending flat surface |
| collinear | lie on same line |
| noncollinear | do not lie on same line |
| coplanar | lie in same plane |
| noncoplanar | do not lie in same plane |
| segment | piece of a line with two endpoints |
| congruent | equal |
| intersection | "crossing" |
| bisector | splits something in two equal parts |
| ray | starts at endpoint- extends forever in one direction |
| angle | two rays with common endpoint |
| vertex | the common endpoint in an angle |
| acute | less than 90 degree angle |
| right | exactly 90 degree angle |
| obtuse | greater than 90, less than 180 degrees |
| straight angle | exactly 180 degrees |
| supplementary | angles add to 180 degrees |
| complementary | angles add to 90 degrees |
| adjacent | angles with same vertex and a common side |
| perpendicular | lines that intersect at a 90 degree angle |
| vertical angles | "opposite" angles |
