1. Geometry Drill
1/24/13
Pick up a paper and use your
protractor to find the sum of the
interior angles of the polygons
that have a check next them.
Write down the sum and the
number of sides

2. Geometry Drill
1/24/13
1. What is the sum of the
angles of a triangle?
2. What is the sum of the
angles of a square?

3. Objective:
To determine the interior
and exterior angle sum in
any polygon.
To determine the measure of
one interior & one exterior
angle of a regular polygon.

4. POLYGON......
1.A CLOSED PLANE FIGURE
2. EACH SEGMENT INTERSECTS
EXACTLY TWO OTHER
SEGMENTS ONE AT EACH
ENDPOINT.
3. MADE OF 3 OR MORE
SEGMENTS

5. WHICH ARE POLYGONS?
1 2 3
5 6
4

6. Convex or Concave
Polygons ?
1 2
5 6

7. Convex Polygons
1
5

8. CONVEX POLYGON
A polygon in which any line
segment connecting two
points has no part outside
the polygon.

9. CONVEX POLYGON
.

10. Sides Interior Angle Sum
3 180
4 360
5 540
6 720
7 900
8 1080
9 1260
10 1440
n

11. Conjecture/Formula
The sum of the
measures of the
angles of a convex
polygon with n sides
is _ .

12. Conjecture/Formula
The sum of the
measures of the
angles of a convex
polygon with n sides
is 180(n–2) _ .

13. How many
exterior angles
are in the
drawing?
Α
E Β
D C

14. exterior angles
Α
Β
E
D C

15. 10 exterior
angles
Α
Β
E
D C

16. We will only be
interested in ONE
AT A VERTEX
Α
Β
E
D C

17. Conjecture/ Formula
The sum of the measures
of the exterior angles of
any convex polygon, one
at each vertex is _____.

18. Conjecture/ Formula
The sum of the measures
of the exterior angles of
any convex polygon, one
at each vertex is 360º.

19. Regular Polygon
A polygon with all sides
and angles congruent.

20. Conjecture/Formula
The measure of one interior
angle of any regular convex
polygon is _____.

21. Conjecture/Formula
The measure of one interior
angle of any regular convex
polygon is
180(n–2)
n

22. Conjecture/Formula
The measure of one
exterior angle of any
regular convex polygon is
_____.

23. Conjecture/Formula
The measure of one
exterior angle of any
regular convex polygon is
360º
n