91Ó°ÊÓ

The theorem for the sum of interior angles for convex polygon states that the sum of measures of the interior angles of a convex polygon with sides is $\left(\mathit{n}-2\right)180$.

The number of sides in a quadrilateral is 4.

Therefore, the value of$n$ is 4.

By using the theorem for the sum of interior angles for convex polygon, the sum of the interior angles for the polygon having 4 sides is given by:

$$\begin{gathered} \left(4−2\right)180=2×180 \\ =360 \end{gathered}$$

Therefore, the sum of interior angles for the quadrilateral is $360°$.

The theorem for the sum of exterior angles for convex polygon states that the sum of measures of the exterior angles of a convex polygon is $360°$.

The number of sides in a quadrilateral is 4.

Therefore, the value of$n$ is 4.

By using the theorem for the sum of exterior angles for convex polygon, the sum of the exterior angles for the polygon having 4 sides is $360°$.

Therefore, the sum of exterior angles of the quadrilateral is $360°$.