Question

梯形ABCD中,AB//CD,A=90,AB=3cm,CD=2cm,AD=7cm,在AD上取一点P,连接PC,PB、△A

Answer 1

1设PA为acm,PD为（7-a）cm

则3/2=a/7-a

解之得a=4.2

所以PA的长度是4.2cm