If the ratio between the interior and exterior angles of a regular polygen is 8:1, then the polygen has - sides.
18
Let each interior angle (i∘)=8x∘ and
Each exterior angle (e∘)=x
We know ,
i∘+e∘=180∘8x+x=1809x=180x=20∘∴e∘=20∘x=360∘e∘=360∘20∘=18