数对 (2,2),(5,2)(3,4)(6,4)是四边形的四个顶点,这个四边形绕点(6,4)顺时针旋转90度后,其他三个顶点用数对 ( , ),( , ),( , )表示.
(1) == %=4: = ÷25=四成(2)1.25= %== :8= ÷16=16: .
12÷16= :80=2.4: = %;2与它倒数的比是 .
8÷ = :4=0.25== %== ÷45=3: = %==.
= %= ÷40=40: .
32÷ == :8= %= (小数)