A | B |

sides | the line segmant or surface that encloses something |

vertex | a point where two sides of a polygon intersect |

degree | the unit of measure for an angle |

protractor | an instrument used to measure angles |

acute angle | an angle that measures less than 90 degrees |

obtuse angle | an angle that measures more than 90 degrees |

right angle | an angle that measures 90 degrees |

straightedge | a ruler or any object with a straight side that can be used to draw a line |

line segment | a series of points with a beginning and an end |

ray | a series of points with a beginning that continues in the opposite direction |

polygon | a many sided closed figure |

vertices | the plural of vertex |

triangle | a 3-sided figure |

quadrilateral | a 4-sided figure |

parallel | two lines that never meet or cross each other |

parallelogram | a quadrilateral that has both pairs of opposite sides equal and parallel |

pentagon | a 5-sided figure |

hexagon | a 6-sided figure |

octagon | an 8-sided figure |

equilateral triangle | a triangle with 3 equal sides |

symmetry | any line that divides a shape or object into matching halves |

congruent | figures having the same size and shape |

similar | figures having the same shape but different size |