Answer:

Explanation:
the picture of the question in the attached figure
step 1
Find the measure of the interior angle of a regular nonagon
The formula to calculate the measure of the interior angle in any polygon is given by

where
n is the number of sides
In this problem we have
n=9 sides
substitute

step 2
Find the value of x
Remember that
The sum of the interior angle and the exterior angle in any vertex of the polygon must be equal to 180 degrees
so

solve for x
