A nonagon has 9 sides and a decagon has 10 sides
The 2-dimensional shape with one more vertex / side is a decagon.
A nonagon here are all the shapes and sides for help all are 2D shapes Circle=1 Not sure about this one Triangle=3 Square=4 Pentagon=5 hexagon=6 heptagon=7 octagon=8 nonagon=9 decagon=10
8 side = octagon 9 side= Nonagon 10 side= decagon
A decagon has 10 sides.
7
a decagon has 10 sides- the stem deca- means ten and -gon means side, therefore decagon means a ten-sided object
It has ten sides.
Seven
360 degrees. Remember for each polygon, for each additional side add 180 degrees. Hence triangle(3) = 180 Quadrilateral(4) = 360 Pentagon(5) = 540 Hexagon(6) = 720 Heptagon(7) = 960 Octagon(8) = 1140 Nonagon(9) = 1320 Decagon(10) = 1500 et.seq.,
A nonagon has 9 sides
A 7 sided heptagon contains 5 triangles.