Let's start by finding the value of Then, we will use its value to find
To find the value of we need to know the relationship between the with measures and Let's analyze the given diagram.
These are . The tells us that corresponding angles formed by and a are . Therefore, these angles are congruent and their measures are the same.
Let's solve this equation!
Now, we can find the value of
The angles with measures
form a . This tells us that they are . Therefore, the sum of their measures is
Since we already know that
we can substitute this value in the above equation, and solve for