从直线外一点,分别向已知直线画垂直线段和斜线,其中 最短.
0.75= :28== %=24÷ .
18÷ = ÷25=0.6==.
=0.25==27÷ = ÷48.
12: == : = :12.
=15÷ = ÷30=七五折= %