4
rectangle
A trapezoid
rhombus
Trapazoid
No, a decagon is not a quadrilateral.
guadrilateral
different shapes that goes slant side
it is a square
A 4 sided quadrilateral can never have 4 obtuse angles.
a crescent has 19 sides
No because the 4 interior angles of a 4 sided quadrilateral must add up to exactly 360 degrees.