Answer:
60
Step-by-step explanation:
y = ½ x + 4
....................
DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD
x = 30
a) The sum of the angles along the line is 180°. That means ...
2x° +90° +x° = 180°
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b) Subtracting 90° and dividing by 3° gives ...
3x° = 90°