Find the number of sides of a regular polygon, if the exterior angle is one – third of
its interior angle.
Answers
Answer:
8 sides
Step-by-step explanation:
A regular polygon is a polygon whose sides are of equal length.
Let us suppose that the interior angle of the regular polygon is given by x
.
Then the exterior angle of the polygon being one-third of the interior angle of the same regular polygon is given by 13x
.
Now we know the exterior angle property for a regular polygon which says that the sum of the adjacent interior and exterior angle is 180∘
.
Using this we get that
13x+x=180∘
On solving the above equation to find the value of x
, we get
x(13+1)=180∘
⇒x(43)=180∘
⇒x=34×180∘
⇒x=3×45∘
⇒x=135∘
Thus, the interior angle of the regular polygon is given by 135∘
.
Thus, the exterior angle of the regular polygon is given by 135∘3=45∘
.
Now the number of sides of the regular polygon is given by 360exteriorangle
.
Substituting the value of the exterior angle of the given polygon in the above formula we get,
36045=8
Therefore the given regular polynomial has 8 sides. Hence it is a regular octagon.