Transcript Bellwork - Haiku Learning

Bellwork
(on ½ sheet—turn in)
• An angle of a triangle is 50. Find the
measure of the angle formed by the
angle bisectors of the other two
angles.
• If the measure of each interior angle
of a regular polygon is 172 find the
number of sides of a polygon.
7.4 Sum of the
Exterior Angles
Students will be able to find the
sum of the exterior angles of a
polygon and one exterior angle
of a regular polygon.
Exterior Angles (defn)
• Name the exterior angle of this
triangle?
• What is true about the sum of an
interior and exterior angle?
• How many exterior angles are in a
heptagon?
Discover
Together we will discover the formula
for the sum of the exterior angles of
a polygon.
Exterior Angle Summary
(Toolbox!)
Se=360
E=
360
n
# of Diagonals Formula
(Toolbox!)
•d=
n( n  3)
2
Example 1
• Find the sum of the exterior angles
of a convex heptagon.
• What is the measure of an exterior
angle of an equiangular heptagon?
Example 2
• If the measure of an exterior angle
of a regular polygon is 15, how
many sides does the polygon have?
Example 3
• Find the measure of each interior
and exterior angle of a dodecagon.
Example 4
• What is the name of an equiangular
polygon if the ratio of the measure of
an interior angle to the measure of
an exterior angle is 3:1?
Ticket to Leave
• What is the measure of each interior
and exterior angle of a regular 18gon?
Homework
• Pg. 309 # 3, 6, 8, 11b, 13, 14
• Pg. 316 # 1, 3, 11-13
• Quiz TOMORROW—Study All 5 Formulas!
Example 5
A polygon has 54 diagonals, how many
sides does it have?
Extra Credit
• In what polygon is the sum of the
measures of the exterior angles, one
per vertex, equal to the sum of the
measures of the angles of the
polygon?
• Due Friday. Show all work for a full
solution.
Extra Credit
• In what polygon is the sum of the
measures of the exterior angles, one
per vertex, equal to the sum of the
measures of the angles of the
polygon?
• Due Friday. Show all work for a full
solution.
Extra Credit
• In what polygon is the sum of the
measures of the exterior angles, one
per vertex, equal to the sum of the
measures of the angles of the
polygon?
• Due Friday. Show all work for a full
solution.
Extra Credit
• In what polygon is the sum of the
measures of the exterior angles, one
per vertex, equal to the sum of the
measures of the angles of the
polygon?
• Due Friday. Show all work for a full
solution.
Extra Credit
• In what polygon is the sum of the
measures of the exterior angles, one
per vertex, equal to the sum of the
measures of the angles of the
polygon?
• Due Friday. Show all work for a full
solution.
Extra Credit
• In what polygon is the sum of the
measures of the exterior angles, one
per vertex, equal to the sum of the
measures of the angles of the
polygon?
• Due Friday. Show all work for a full
solution.
Extra Credit
• In what polygon is the sum of the
measures of the exterior angles, one
per vertex, equal to the sum of the
measures of the angles of the
polygon?
• Due Friday. Show all work for a full
solution.