The sum of the interior angles of an n sided figure is (n-2)*180 degrees So for an 8 sided figure, the sum is 6*180 = 1080 degrees.
A nine sided plane figure is a nonagon. A nine sided three dimensional figure is a nonahedron.
nine sided figure = nueve figura una cara nonagon = nonágono
nonagon
Nonagon
A nine sided figure.
The sum of the angles of an 8 sided octagon add up to 360 degrees
7
900°
It is called a nonagon. There currently is no official name for a nine-sided polygon. However, two names have been proposed for such a figure: the first is a Nonagon; the second is an Enneagon.
The sum of a 10 sided figure is 1440 To solve it or the sum of any other figure you do this... 180(n-2) n equals the number of sides the figure has 180(10-2) 180(8) 1440
900 degrees