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Unit 2 voc.
| Question | Answer |
|---|---|
| `Three undefined terms in geometry | points, lines, and planes |
| point | has no length, width, or thickness, but has a position. |
| space | is the boundless 3-dimensional set of all points. |
| line | has length, but no width or thickness. it extends without end in two directions. |
| collinear points | points that lie on the same line are collinear points. |
| plane | is a flat surface that has no thickness. it extends without end in all directions. |
| coplanar | points and lines in the same plane |
| intersecting lines | lines shaes a point |
| intersecting planes | share an indefinite number of points who two planes intersect, the intersection is a line |
| postulate | a statement accepted to be true without proof |
| postulate 1-1 | through any two points there is exactly one line |
| postulate 1-2 | if two lines intersect then they intersect in exactly one point. |
| postulate 1-3 | if two planes then they intersect in axactly one line. |
| postulate 1-4 | through any three noncollinear points there are exactly one plne. |
| line segment | is a portion or a line between two points, called endpoints |
| ray | is a part of a line that consists of an initial point and all points on the line that lie on the side of the initial point. |
| opposite rays | start at the same point and go in opposite directions. |
| parallel lines | are coplanar lines that do not intersect |
| skew lines | are noncoplanar lines. therefore, they are ot parallel and not intersect. |
| perpendicular lines | lines intersect to form right angles. |
| parallel planes | are planes that do not intersect |
| Ruler Postulate | the distance betwwen any two points on a number line is a absolute value of the difference of the corresponding numbers. |
| congruent segments | twos egments with the same length. |
| midpoint of a segment | a pont that divides a segment into two congruent segments. it bisects the segment.i |
| bisector of a segment | any line, ray or other segment through a midpoint. |
| angle | two arys that are connected at their endpoints |
| protractor | device used to measure angles |
| acute angle | less than 90% |
| obtuse angle | greater than 90% |
| right angle | exactly 90% |
| congruent angles | with the same measures |
| angle bisector | ray that divides an angle into 2 congruent(=)angle |
| inductive reasoning | is a type reasoning that reaches conclusions based on a pattern of specific eaxamples or past events |
| counterexample | is an example that proves a conjectures is false. |
| conjecture | a conclusion reaches by using inductive reasoning. |