# Classifying 2-D Figures

### 5.5A

## Vocabulary Focus

## Congruent having the same size and shape | ## Degree a unit of measure for angles and temperature | ## Equilateral Triangle a triangle with three congruent sides and three congruent angles |

## isosceles triangle a triangle with two congruent sides and two congruent angles (?) | ## kite a quadrilateral with two pairs of congruent, adjacent sides | ## obtuse angle an angle that measures more than 90 degrees but less than 180 degrees |

## Obtuse Triangle a triangle that has one angle greater than 90 degrees | ## Parallel Lines Two lines that are in the same plane that never intersect. | ## Perpendicular lines intersecting at right angles. |

## Polygons A closed figure made out of segments | ## Quadrilateral a polygon with four sides and four angles | ## Rectangle a parallelogram with four right angles |

## Rhombus a parallelogram in which all four sides are congruent and opposite angles are congruent | ## Right Angle an angle with a measure of 90 degrees | ## Right Triangle a triangle with one right angle |

## Trapezoid a quadrilateral with one pair of parallel sides | ## Triangle a three sided figure | ## 2-Dimensional Figures a plane figure that has length and width: area and perimeter |

## Regular Polygon a polygon in which all sides and all angles are congruent | ## Irregular Polygon a polygon with sides and angles that are not congruent or equal | ## Pentagon A 5 sided polygon |