Answer:
1. a. 900° b. 1980°
2. Nonagon
Explanation:
In order to find the interior angles of a polygon, use the formula,
Sum of interior angles = (n-2)*180°
For
a. Heptagon
no of side =7
The sum of the interior angles of a heptagon:
(7-2)*180 = 900°
b. 13-gon
no. of side =13
The sum of the interior angles of a 13-gon:
(13-2)*180 = 1980°
2.
The sum of the interior angles of a convex polygon is 1260°,
where n is the number of sides.
In this case, we have
1260 = (n-2)*180
1260/180=n-2
n-2=7
n=7+2
n=9
Therefore, the polygon has 9 sides and is classified as a nonagon.