Download Notes: 6-1 Angles of Polygons Diagonal – Polygon # of Sides # of

Notes: 6-1 Angles of Polygons
Diagonal –
Polygon
# of Sides
# of Triangles
Sum of Interior
Angle Measures
Triangle
Quadrilateral
Pentagon
Hexagon
n-gon
How do you calculate the sum of the interior angles of a polygon?
Theorem 6.1 – Polygon Interior Angles Sum
Review: Naming Polygons
# of Sides
Polygon
3
4
5
6
7
8
# of Sides
9
10
11
12
n
Polygon
Example 1: a. Find the sum of the measures of the
interior angles of a convex heptagon. Measure the
heptagon below with a protractor to see if your sum is
correct.
b. Find the measure of each interior angle of
quadrilateral ABCD.
Example 2: The poles for a tent form the vertices of a regular
hexagon. When the poles are properly positioned, what is the measure
of the angle formed at a corner of the tent?
Polygon Exterior Angle Sum
What do you notice about the exterior angles of a polygon?
Notes: 6-2 Parallelograms
Parallelogram –
Example 1: In parallelogram ABCD, suppose m<A = 55, AB = 2.5 feet,
and BC = 1 foot. Find each measure.
a. DC =
b. m<B =
c. m<C =
Example 2: If QRST is a parallelogram, find the value of the
indicated variable.
a. x
b. y
c. z
Geogebra Activity:
Draw parallelogram ABCD with vertices at A(5,1), B( 2, 1), C(4,5),
D(7,5).
Cut and paste your parallelogram here:
A. Use the Midpoint Formula to determine if the diagonals of
ABCD bisect each other.
B. Determine whether the diagonals are congruent.
C. Use slopes to determine if the consecutive sides are
perpendicular. Explain.