Answer:
well i mean i guess you know what it is
Explanation:
We know that all of the angles in a triangle must add up to 180. so to find the measure of angle b, we can add the two known angles together, and take that number away from 180. (we would do this to find out how much is left to complete a full 180 degrees) 115+31=146. 180-146=34. since all of the angles 31, 115, and 34 add up to 180, we know that 34 is the correct answer
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