A | B |

right angle | A 90 degree angle |

equilateral triangle | A triangle with all sides and angles equal. |

scalene triangle | A triangle having three unequal sides and angles. |

vertex | The intersection point of two sides. |

right triangle | A triangle with one angle equal to 90 degrees. |

acute angle | An angle less than 90 degrees. |

obtuse angle | An angle greater than 90 degrees. |

isosceles triangle | A triangle with two sides of equal length. |

acute triangle | A triangle with all angles less than 90 degrees. |

obtuse triangle | A triangle with one angle greater than 90 degrees. |