1. Geometry Vocabulary

2. polygon- a closed figure formed by 3 or more line segments
quadrilateral- polygon with 4 sides and 4 angles
rhombus- a parallelogram with 4 congruent sides
rectangle- a parallelogram with 4 right angles
square- a polygon with 4 equal sides
trapezoid- a quadrilateral with exactly one pair of parallel sides
hierarchy- a system for organizing things
attribute-a characteristic of a shape

3. triangle- polygon with 3 sides and 3 angles
right triangle- triangle with one 90 degree angle
acute triangle- triangle with 3 angles measuring less than 90 degrees
obtuse triangle- triangle with one angle greater than 90 degrees
equilateral triangle- all 3 sides are congruent (equal)
scalene triangle- no sides are congruent (equal)
isosceles triangle- 2 sides are congruent (equal)

4. regular polygon- all sides and angles are congruent
irregular polygon- not all sides and angles are congruent
pentagon- a polygon with 5 sides
hexagon- a polygon with 6 sides
heptagon- a polygon with 7 sides
octagon- a polygon with 8 sides
nonagon- a polygon with 9 sides
decagon- a polygon with 10 sides
circle- a closed figure with all points on the figure the same distance from the center point

7. 20 Sided Polygon- Icosagon

8. Review Vocabulary-
two dimensional-shape that only has two dimensions (such as width and height) and no thickness
parallel- lines that do not intersect
perpendicular- 2 lines that intersect to form right angles
congruent- having the same size and shape
right angle- an angle that measures 90 degrees