If angle a has a measurement of 42 and is complementary to angle b whats the measure of angle b

48 degrees. a complementary angle has to equal 90 degrees so you have to take 90 and subtract 42 and the answer is 48 

32

step-by-step explanation:

these are your clues: 1. kim ran 18 races2. this was four fewer races than twice thenumber, notice it says twice the number, so you would do the equation 18x2-4; which equals the number 32.thus, 32 is your answer.