Download Warm Up: Investigating the Properties of Quadrilaterals

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.
m1 + m2 + m3 + m4 = 3600
2
1
4
3
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
C
F
D
E
• 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.