Answer:

<u>Skills needed: Angle Geometry</u>
Step-by-step explanation:
1) First, let's see what we should know prior to solving. 
---> We have to find the value of  , and looking at that diagram, we have to create an equation.
, and looking at that diagram, we have to create an equation. 
---> The angle measure of a straight line is 180 degrees, otherwise known as a straight angle (a straight angle is 180 degrees). 
---> When you add  , you can set that sum equal to 180. This is because the two angles marked
, you can set that sum equal to 180. This is because the two angles marked  added together make a straight line, which is a straight angle.
 added together make a straight line, which is a straight angle. 
(Note: In geometry, ONE OF THE THINGS WE CAN ASSUME is that there is a straight line there.)
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2) Now, the equation would be: 

 --> Combining
 --> Combining  and
 and  (3+3 = 6)
 (3+3 = 6)
 --> Dividing by 6 on both sides, to get
 --> Dividing by 6 on both sides, to get  by itself.
 by itself. 
 --->
 --->  is 30, so
 is 30, so  is equal to 30.
 is equal to 30. 
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