A 3 sided shape is a triangle. A 4 sided shape could be a square or rectangle.
A 3-sided shape is called a triangle.or Polygon in general.
A triangle is a 3 sided shape. There are a few types, Isosceles, Scalene (Acute and Obtuse), Equilateral and the Right angle triangle.
10 sided 2D shape is called a decagon 20 sided 2D shape is called a icosagon 30 sided 2D shape is a swimming pool 40 sided 2D shape is unknown 50 sided 2D shape is unknown 60 sided 2d shape is unknown 70 sided 2d shape is unknown 80 sided 2d shape is unknown 90 sided 2d shape is unknown 100 sided 2d shape is unknown 110 sided 2d shape is unknown 111 sided 2d shape is unknown 120 sided 2d shape is unknown 130 sided 2d shape is unknown
it is called a triangle
it is called a seven sided shape in Canada
a one sided shape is called a henagon and a 2 sided shape is called a digon
a polyhedron (if the shape is 3 dimensional) a polygon if it is a planar shape.
A heptahedron
Octahedron
A heptagon.
Hendecahedron