Answer:
b = 57
c = 123
Explanation:
Knowing that a straight line (supplementary angle) makes 180 degrees.
Therefore,
b + 123 = 180
b + 123-123 = 180-123
b = 57
Vertical angles are angles opposite each other where two lines cross.
if two lines intersect and make an angle like x = 30° then its opposite angle is also equal to 30°. And the angle adjacent to angle x will be equal to 180 – 30 = 150°.
Therefore in this image we can know that opposite side of 123° which is c is also 123°.
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Refer to the image below: