Given:
To find:
The size of the unknown angle "x"
Solution:
The given polygon is a Pentagon so the sum of interior angle will be,

n means the number of sides
Let's substitute the values according to the formula.


Now, we can find the sum of one interior angle.

n means the number of sides.
Let's substitute the values according to the formula.


Therefore, the size of the unknown angle "x" is 108°