absolute value a real number regardless of its sign |

acute triangle a triangle whose interior angles are all acute |

bisector the line that divides something into two equal parts |

corresponding angles when two lines are crossed by another line, the angles in matching corners |

discount give reduction in price on; an amount or percentage deducted |

equilateral triangle a three-sided regular polygon |

experimental probability the ratio of the number of outcomes in which a specified event occurs to the total number of trials, not in a theoretical sample space but in an actual experiment. |

exponential notation scientific notation, a way of writing numbers that are too big or too small to be conveniently written in decimal form |

exterior angles the angle between a side of a rectilinear figure and an adjacent side extended outward |

interest the power of attracting or a fixed charge for borrowing money; usually a percentage of the amount borrowed |

interior angles the angle between adjacent sides of a rectilinear figure |

isosceles triangle a triangle with two equal sides |

negative less than zero; having a negative charge; reckoned in a direction opposite to that regarded as positive |

obtuse triangle a triangle that contains an obtuse interior angle |

outcome result; end or consequence; result of a random trial |

permutations rearrangement of the elements of a set |

positive involving advantage or good ; greater than zero; very sure; confident |

radical sign a sign indicating the extraction of a root |

ratio relation which one quantity or magnitude has to another of the same kind; rate; proportion |

regular polygon a polygon with all sides and all angles equal |

rhombus a parallelogram with four equal sides; an oblique-angled equilateral parallelogram |

right triangle a triangle with one right angle |

scale factor a number used as a multiplier in scaling |

scalene triangle a triangle with no two sides of equal length |

theoretical probability the probability that a certain outcome will occur, as determined through reasoning or calculation. |

transversal extending or lying across; in a crosswise direction; at right angles to the long axis |

unit rate the estimated market value contribution for each unit of an improvement |

vertical angle either of two equal and opposite angles formed by the intersection of two straight lines |