Answer:
Part 17)

Part 18)

Explanation:
Part 17) What is the sum of the measures of the interior angles of a dodecagon?
we know that
The sum of the interior angles in a polygon is equal to

where
n is the number of sides of polygon
In this problem we have
n=12 sides (dodecagon)
substitute the value of n in the formula



Part 18) Find the measure of angle WZX
step 1
Find the value of x
we know that
An exterior angle of a triangle is equal to the sum of the opposite interior angles
so

solve for x
Group terms

Combine like terms


step 2
Find the measure of angle WZX

substitute the value of x
