Answer:
Regular polygon with interior angle as
is not possible.
Solution:
Need to find the type of regular polygon whose internal angle is

Consider AB be the first side of the regular polygon and BC be the second side. Since required interior angle =
, so ∠ABC =
that means ABC is a straight line.
Now let say CD be the third side of regular polygon of interior angle
. So ∠BCD =
, which means point ABCD are on same line .So we can say whenever we try to make a regular polygon of interior angle
. we get straight line only.
So closed curve is never possible with interior angle

Hence regular polygon with interior angle as
is not possible.