1. Daily Warm-Up
Find EF.
Find the midpoint of the segment ED with endpoints E(8,-9) and D(0,5)
Find the length of segment CF with endpoints C(4,6) and F(-4,-3).
x+15
7x-3 E F M

2. Perimeter & Area in the Coordinate Plane 1.4

3. Core Concepts
 Polygon—a closed plane figure formed by three or more line segments called sides.   
Number of Sides
Type of Polygon 3
Triangle 4
Quadrilateral 5
Pentagon 6
Hexagon 7
Heptagon 8
Octagon 9
Nonagon 10
Decagon 12
Dodecagon n
n-gon

4. Core Concepts
 Polygon—a closed plane figure formed by three or more line segments called sides.
Example 1:  
Triangle Decagon Quadrilateral gon

5. Core Concepts
Vertex— the point of intersection of two sides of a polygon.
Convex—when no line that contains a side of the polygon contains a point in the interior of the polygon
Concave—A polygon that is not convex.

6. Example 2 Concave Convex Convex
Classify each polygon. (2) Name all the vertices for each polygon shown. (3) Determine whether the polygon is convex or concave.
Hexagon dodecagon Octagon
A, B, C, D, E, F A,B,C,D,E,F,G,H,I,J,K,L A,B,C,D,E,F,G,H
Concave Convex Convex

7. Perimeter & Area Review
Core Concepts
Perimeter & Area Review
Triangle

8. Perimeter & Area Review
Core Concepts
Perimeter & Area Review
Square

9. Perimeter & Area Review
Core Concepts
Perimeter & Area Review
Rectangle

10. Example 3
Find the perimeter & Area of with vertices A(-2,3), B(3,-3), & C(-2,-3).

11. You Try #1:
Find the perimeter & Area of with vertices C(1,3), D(4,-3), & E(-4,-4)

12. Example 4
You are building a shed in your backyard. The diagram shows the 4 vertices of the shed. Each unit in the coordinate plane represents 1 foot. Find the area of the floor of the shed.