1. **please place homework on corner of your desk 
Warm Up – Find the coordinate of the midpoint of AB and also the length of the segment (AB)
x₁ + x₂ 2
y₁ + y₂ 2 A B

2. Classifying Polygons & Finding Perimeter & Area

3. Classifying Polygons
Polygon – a closed figure in a plane that is formed by 3 or more sides. The point where two sides intersect is called a vertex. You can name a polygon by listing the vertex points in order.
Vertex D E B C A
Side ED
(is a line segment)
Polygon ABCDE

4. Classifying Polygons
You can also name of a polygon by the number of sides, where “n” is the number of sides.
A polygon is convex when it has no angles pointing inward. A polygon is concave when some angles point inward.
Hint: a rubber band would fit snugly around a convex polygon, leaving no gaps. The concave one would have gaps (like a cave).

5. Name the polygon according to the number of sides it has:
Name That Polygon
Name the polygon according to the number of sides it has:
Hexagon
Pentagon
Decagon
Triangle
Quadrilateral

6. Review of Perimeter and Area of Polygons
Perimeter – distance around a shape. It has linear units (like feet, inches, etc.)
5 in.
3 in.
3 in
Perimeter is = 16 inches
Area – the amount of space inside the boundary of a shape. It has square units (like ft², in², etc.)
in.
Area is 9 x 4 = 36 square inches

7. Formulas for Perimeter and Area of Polygons
P = a + b + c
A = 𝟏 𝟐 𝐛𝐡
P = 4s
A = s²
P = 2L + 2W
A = LW

8. Example: Perimeter and Area of Polygons
Mrs. York adopted a dog that is crazy and out of control (true story.. his name is Clark). She needs to build an enclosed, rectangular dog run in her yard that will have the greatest possible area for him to run around. She has 100 feet of fencing. What would the length and width of the dog run need to be to maximize the area?