In a geometric diagram angle a and angle B are complementary and they form a straight line with angle C if angle a equals X be angle B( x and angle C equals 90°, what is the measure of angle B
In a straight line, the sum of the angles is always 180°.
Since angle C is 90°, and angles a and B are complementary, their sum is also 90°.
Therefore, angle B measures 90° - angle a or 90° - X.