如图,∠AOC和∠BOD都是直角,如果∠DOC=36°48′,则∠AOB是 度.
÷8=21÷ == : = (小数).
÷ ==3: = :24= (填小数)
0.12=== ÷ =24: .
:5=== ÷25= (写小数).
12÷ ==0.375= :64= ÷24.