1. What did we discover so far?

2. Why is this building famous in America? What type of Pentagon is it?
THE PENTAGON
REGULAR
United States Defence Headquarters
Why is this building famous in America?
What type of Pentagon is it?
So, can you figure out the value of each interior angle? 2

3. Why can we find the value of one interior angle in this case?
It is a REGULAR polygon
The angles are all the same
So I can find one angle by dividing by the number of angles!
The sum of interior angles of ANY polygon can be found using the formula: (n – 2) x 180
I can only find one interior angle if it is a REGULAR polygon : 𝒏−𝟐 × 𝟏𝟖𝟎 𝒏

4. Sum of Exterior Angles of any Polygon = 360°
Question:
How much is one exterior angle of a regular pentagon?
One exterior angle of a regular pentagon = 𝟑𝟔𝟎 𝟓 =𝟕𝟐°
In general: 𝟑𝟔𝟎 𝒏
Summary Sheet