click below

click below

Normal Size Small Size show me how

# Fennville Geo Unit 1

### review of key ideas for unit 1 geometry

Term | Definition |
---|---|

point | names a location. represented by a dot. |

line | straight path through two or more points that extends forever. |

segment | part of a line consisting of two endpoints and all points between them. |

ray | part of a line that starts at an endpoint and extends forever in one direction. |

angle | formed by two rays with the same endpoint. |

acute angle | angle that measures greater than zero and less than 90 degrees |

right angle | angle that measures exactly 90 degrees |

obtuse angle | angle that measures greater than 90 degrees and less than 180 degrees |

straight angle | angle formed by two opposite rays and measures exactly 180 degrees |

angle bisector | a ray that divides an angle into two congruent angles. a ray that splits an angle in half. |

bisect | to cut in half |

collinear points | points that lie on the same line |

non-collinear points | three or more points that do not lie on the same line |

coplanar | points that lie on the same plane |

congruent angles | angles which have the same measure |

complementary angles | two angles that add to 90 degrees |

supplementary angles | two angles that add to 180 degrees |

distance | absolute value of the difference of the coordinates of two points on a number line |

linear pair of angles | two adjacent angles that form a straight angle or line. |

adjacent angles | two angles with the same vertex that share a side but do not share any interior points. |

non-adjacent angles | two angles that are not adjacent. |

plane | flat surface that has no thickness and extends forever; formed by three non-collinear points |

vertical angles | two non-adjacent angles formed by two intersecting lines. |

midpoint of a segment | point exactly in the middle of a segment. |

reflection | transformation across a line (flip) which produces congruent figures with opposite orientations |

rotation | transformation about a point (turn) which produces congruent figures with the same orientation |

translation | transformation in which all points move the same distance in the same direction (slide) which produces congruent figures with the same orientation |

transformation | a change in the position, size, or shape of a figure. |

opposite rays | two rays that have a common endpoint and form a line. |

AC | by the segment addition postulate, when point B is between points A and C on segment AB, AB + BC = |

ABD | by the angle addition postulate, measure of angle ABC + measure of angle CBD = measure of angle |