ABCD is a parallelogram with diagonal AC. If a line XZ is drawn such that XZ∥AB and cuts AC at Y, prove that BX/XC=AZ/ZD.
Given: AB || XZ
In ΔABC, AB || XY
Therefore BX/XC = AY/YC ….. (1)
In parallelogram ABCD, AB || CD
AB || CD || XZ
In ΔACD, CD || YZ
Therefore AY/YC = AZ/ZD ….( 2)
From (1) and (2)
BX/XC = AY/YC = AZ/ZD
So, BX/XC = AZ/ZD
Hence proved