In a geometric diagram, ∠A and ∠B are complementary, and they form a straight line with ∠C . If m∠A=x° , m∠B=(2x)° , and m∠C=90° , what is the measure of ∠B ?(1 poin

Since ∠A and ∠B are complementary, their measures add up to 90 degrees.

Therefore, x + 2x = 90

Combining like terms, we get 3x = 90

Dividing both sides by 3, we find x = 30

Since ∠B is 2x, we multiply 30 by 2 to get the measure of ∠B.

∠B = 2(30) = 60 degrees

Therefore, the measure of ∠B is 60 degrees.