四边形ABCD相似四边形A’B'C'D',而且AB:BC:CD:DA=1:1/2 :2/3 :2,若四边形A’B'C'D'的周长为100CM,四边形ABCD相似四边形A’B'C'D',而且AB:BC:CD:DA=1:1/2 :2/3 :2,若四边形A’B'C'D'的周长为100CM,求B'C’的长
问题描述:
四边形ABCD相似四边形A’B'C'D',而且AB:BC:CD:DA=1:1/2 :2/3 :2,若四边形A’B'C'D'的周长为100CM,
四边形ABCD相似四边形A’B'C'D',而且AB:BC:CD:DA=1:1/2 :2/3 :2,若四边形A’B'C'D'的周长为100CM,求B'C’的长
答
∵四边形ABCD相似四边形A’B'C'D'
∴AB:BC:CD:DA=A’B':B'C':C'D':D'A’=1:1/2 :2/3 :2
设A’B'=x,B'C'=x/2,C'D'=2x/3,D'A’=2x
∴x+x/2+2x/3+2x=100
x=600/23
B'C'=x/2=300/23