Number
Decagon, if a plane figure or decahedron, if a solid.
Parabola
A pentagon is a five sided geometrical figure; if the pentagon fits exactly inside some other geometrical figure (such as a circle) then it can be said to be inscribed in that figure.
A point.
A pentagon
Try tetradecagon. The name of the geometrical figure with 14 sides is being proposed to be Tetradecagon, Tetrakaidecagon.
A five sided figure is a pentagon.
A geometrical figure that has three angles is a triangle
a polygon?
A triangle
7
A polygon!