Answer:
75°
Step-by-step explanation:
First, we need to know that the interior angle sum of a triangle is always 180°.
Now, to find the missing angle aside from x, we need to complete the sum 180-155=25, seeing 155° lies on a straight line. Remembering
the interior angle sum of a triangle is always 180°, it is thus clear that 25+80+x=180. If we complete this equation, x=75.
Hope this helps!
