Question

在Rt△ABC中,∠C=90度,CD⊥AB,垂足为D,AD=2,BD=1,以C为圆心,以1.4为半径作圆,则此圆和AB的

Answer 1

cd^2=bc^2-bd^2

cd^2=ac^2-ad^2

ac^+bc^2=(ad+bd)^2=9

cd^2=(ac^2+bc^2+ad^2+bd^2)/2=14

cd^2=7

1.4