warm up: investigating the properties of quadrilaterals make a conjecture about the sum of the...
TRANSCRIPT
Warm Up: Investigating the Properties of Quadrilaterals
• Make a conjecture about the sum of the interior angles of quadrilaterals.
• You may use any material/equipment to help test your conjecture.
• Be prepared to justify your conclusion with the data you collect.
• You may choose to work as a group or by yourself.
Interior Angles of a Quadrilateral
The sum of the measures of the interior angles of a quadrilateral is 3600.
m1 + m2 + m3 + m4 = 3600
1
2
34
Chapter 6.1: Polygons
• Students will identify regular and
nonregular polygons.• Students will describe characteristics
of a quadrilateral.
What’s a Polygon?
A plane figure that meets the following conditions…
1. It is formed by three or more segments called sides, such that no two sides with a common endpoint are collinear.
2. Each side intersects exactly two other sides, one at each endpoint.
More Vocabulary
• Vertex (vertices): each end point of a side of a polygon
• Name vertices of a polygon consecutively.
• State whether each figure is a polygon. If not, explain why.
A B CD
E
F
• Convex polygon: a polygon such that no line containing a side of the polygon contains a point in the interior of the polygon. Every internal angle is less than or equal to 180o.
• Concave or Nonconvex polygon: a polygon that is not convex. Always has an interior angle with a measure that is greater than 180o.
• Now draw your own example of a concave and convex polygon.
Concave Convex
• Equilateral: a polygon with all sides congruent
• Equiangular: a polygon with all of its interior angles congruent
• Regular: a polygon that is equilateral and equiangular
• Diagonal: a segment in a polygon that joins two nonconsecutive vertices.
Cool Down: Find the missing values.
1.
2.