Download Polygon Angles.cwk (WP)

Geometry Activity
Polygon Angles
PE 8.2C
Triangle Angles - Use a protractor to measure interior angles 1, 2, and 3 in
the triangle. This is an equilateral triangle so all three should be the same
size.
1
Find the sum of angles 1, 2, and 3.
Draw several other triangles and measure their
interior angles and find their sum.
2
3
What conclusion can you make about the sum of interior angles of any
triangle?
Square Angles - Use a protractor to measure interior angles 1, 2, 3. and 4
in the square. Being a square all 4 angles should be the same size.
Find the sum of the 4 angles.
1
4
2
3
Draw several other 4 sided polygons and measure
their interior angles and find their sum.
What conclusion can you make about the sum of interior angles of any 4
sided polygon?
Pentagon Angles - Use a protractor to measure interior angles 1, 2, 3. 4
and 5 in the pentagon. Since it is a regular pentagon all 5 angles should be
the same size.
1
Find the sum of the 5 angles.
Draw several other 5 sided polygons and measure
their interior angles and find their sum.
5
2
3
4
What conclusion can you make about the sum of interior angles of any 5
sided polygon?
Geometry Activity
Polygon Angles
Hexagon Angles - Use a protractor to measure interior angles 1, 2, 3. 4, 5
and 6 in the hexagon. Since it is a regular hexagon angles should be the
same size.
6
1
Find the sum of the 6 angles.
5
2
Draw several other 6 sided polygons and measure
their interior angles and find their sum.
3
4
What conclusion can you make about the sum of interior angles of any 6
sided polygon?
Regular Polygon Angles - Make a table and list the number of sides of a
regular polygon, the measure of each interior angle and the sums of angles
for regular triangles, squares, pentagons and hexagons. Without measuring
the angles of a heptagon (7 sided polygon) predict the sum of its angles and
the measure of each interior angle. Then measure a 7 sided polygons and
see if you are correct. Use the polygons worksheet to help with this part of
the activity.
Do the same for an Octagon (8 sided polygon).. Continue to predict for
Nonagons (9 sided) and Decagons (10 sided). Make a conjecture that would
allow you to find the size and sum of the interior angles of any number
sided regular polygon.
Table Example:
Polygon Sides Angle Measure
3
4
5
6
7
8
9
10
11
12
any
Total