Question

How many of the given shapes are quadrilaterals?

Answer 1

$\underset{–}{\text{Qualdrilateral:}}$
A closed planar shape with four straight sides is known as quadrilateral.

Now, in given shapes only $3$ shapes (marked as $2,4,8$) satisfy the definition of quadrilateral as shown in below figure,


Shapes numbered $1,3,5,6$ have curved sides and shapes $6$ is not closed, hence they are not quadrilaterals.

Therefore, in given shapes only three shapes are quadrilateral.