acute angle | An angle measuring less than 90º. |

angle | A figure formed by the joining of two rays with a common endpoint. |

line | A line is a one-dimensional figure, which extends without end in two directions. |

line segment | A finite section of a line between any two points that lie on the line. |

obtuse angle | An angle measuring more than 90º and less than 180º. |

plane | In geometry, a two-dimensional surface that continues infinitely. Any three individual points that don't lie on the same line will lie on exactly one plane. |

point | A zero-dimensional object that defines a specific location on a plane. It is represented by a small dot. |

ray | A half-line that begins at one point and goes on forever in one direction. |

right angle | An angle measuring exactly 90º. |

straight angle | An angle measuring exactly 180º. |

vertex | A turning point in a graph. Also the endpoint of the two rays that form an angle. |

vertex | A turning point in a graph. Also the endpoint of the two rays that form an angle. |