I'm pretty sure I didn't do this right...could you check it for me please?

The measure of an exterior angle of a regular n-gon is 72degrees. Classify the polygon by number of sides.

I did the formula (n-2)times 180degrees=72degrees
which led me to n-2=0.4
then n=2.4

Question

I'm pretty sure I didn't do this right...could you check it for me please?



The measure of an exterior angle of a regular n-gon is 72degrees. Classify the polygon by number of sides.

I did the formula (n-2)times 180degrees=72degrees
which led me to n-2=0.4
then n=2.4

ganeshie8 · Answer

looks like you applied the interior angle formula

ganeshie8 · Answer

but they gave exterior angle. do u knw any formula about exterior angle ?

anonymous · Answer

No....

ganeshie8 · Answer

lookup ur notes. there should be a formula for "Sum of Exterior Angles in a polygon"

anonymous · Answer

I found the formula but I'm not sure how to apply it

ganeshie8 · Answer

good :) what it says

anonymous · Answer

the formula is;
m angle1+m angle2+...+m angle n=360degrees

ganeshie8 · Answer

Perfect ! that is enough to knw what polygon it is

ganeshie8 · Answer

since the exterior angle is 72, and all anlges are equal in a regular polygon,

72*n = 360

ganeshie8 · Answer

could u solve for n ?

anonymous · Answer

Yeah

ganeshie8 · Answer

:) what polygon is it

anonymous · Answer

Pentagon...?

ganeshie8 · Answer

thats right ! good work !!

anonymous · Answer

Awesome! Thanks for you help! I understand what I'm doing now :D

ganeshie8 · Answer

glad to hear yw friend :D