Plane Geometry Unit 7 - Quadrilaterals

1
Plane GeometryUnit 7 - Quadrilaterals

• Section 1.6 Classify Polygons
• Day 1

2
WARM-UP

• Grab a worksheet from the front table and
  complete it.

3
What can we classify the object that the
individual is standing on?
PLANE
4
What exactly is a plane?
PLANE 2 dimensional object that extends
infinitely in two directions.
5
What happens if I cut a shape out of a plane?
We have now created a polygon.
6
Okay, so what is a polygon?

• Polygon closed plane figure with the following
  two properties
• It is formed by three or more line segments,
  a.k.a. the sides.
• Each side intersects exactly two sides, one at
  each endpoint, so that no two sides with a common
  endpoint are collinear.

7
What are the parts of a polygon? How do I label
it?
Sides and Vertices (plural of vertex) are the
parts. List the vertices in consecutive order.
A
Label Pentagon ABCDE or Pentagon CBAED
E
Vertex
B
Side
D
C
8
Convex vs Concave?
Convex no line that contains a side of the
polygon contains a point in the interior of the
polygon. Concave line contains a point in the
interior.
Convex
Concave
Point in the interior
Interior
Interior
9
How do we classify?
By the number of sides
Number of Sides Types of Polygon Number of Sides Types of Polygon
3 Triangle 8 Octagon
4 Quadrilateral 9 Nonagon
5 Pentagon 10 Decagon
6 Hexagon 12 Dodecagon
7 Heptagon n N-gon
3
10
Are there special types of polygons?

• Yes, but only for convex polygons
• Equilateral all the sides are congruent
• Equiangular all the angles are congruent
• Regular convex polygon that is both equilateral
  and equiangular

11
1.6 Answers

1. No, curved edges
2. Yes, Concave
3. Yes, Convex
4. Pentagon, Regular
5. Quadrilateral, Equilateral
6. Triangle
7. Hexagon

1. 8x 6 4x 224x 28x 750 feet
2. 3x 63 7x 45-4x -108x 27144o

12
1.6 Answers

• -2x 41 7x - 40-9x -81x 923 km
• Images Vary
• Images Vary
• Images Vary
• Images Vary

1. 2x x 30x 30
2. 3x 32 13x 2710x 5x ½
3. x2 12 2x2 61 x2 49x 7