A complementary angle is an angle that adds up to 90 degree each and every time. So, therefore the correct formula to use is 90-63=27. Now, you have your answer and can check it twice if you'd like by the formula. Again your answer is 27.
There are 14 floors in the building, because since Juan went up 4 floors, down 3 floors, and up one floor; so we know that he is 2 floors above from where he originally started. Once he went down 9 floors he passed the starting point and went to the bottom of the building. So, the middle must have been the 7th floor. Once I knew that I multiplied 7*2 and it got me 14. So in total there are 14 floors. I hope this helped ^^
yes
A rational number is a number which can be expressed in the form
where a and b are integers
now 2. 34 = 2 
= 
→ a rational number
