__ | 1. | Acute angle | | A. | A quadrilateral with one pair of parallel sides. |

__ | 2. | Circle | | B. | A triangle with a obtuse angle. |

__ | 3. | Diagonal | | C. | The opposite angles where two lines meet. |

__ | 4. | Obtuse triangle | | D. | A two dimensional closed figure of straight line segments. |

__ | 5. | Polygon | | E. | A polygon in which all side lengths and angles are equal. |

__ | 6. | Regular Polygon | | F. | A special rectangle with all sides of equal length. |

__ | 7. | Square | | G. | Point where two sides of a polygon meet. |

__ | 8. | Trapezoid | | H. | A set of points at a fixed distance from a point. |

__ | 9. | Vertex | | I. | Connects two vertices of a polygon and is not a side. |

__ | 10. | Vertical Angles | | J. | An angle with measure greater than 0 |