Answer:
B) 55°
Step-by-step explanation:
The ∑ of all interior angles of a triangle is 180°. 
When you see a square in a angle (as seen in the bottom left of the triangle), it means that it is a right angle, or 90° in measurement. 
Set the equation: 
180 = x + 90 + 35
First, combine like terms: 
180 = x + (90 + 35)
180 = x + 125
Next, subtract 125 from both sides of the equation to isolate the x: 
180 (-125) = x + 125 (-125)
x = 180 - 125
x = 55
55°, or B) is your answer.
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