Q.

ABCD is a trapezium with AD∥BC and AD = 4cm. If the diagonals AC and BD intersect each other at O such that AO/OC = DO/OB =1/2, then BC =

1 6 cm  
2 7 cm  
3 8 cm  
4 9 cm  

Ans.

(3)

AD∥BC

and AOOC=DOOB=12

∴  ADBC=AOOC⇒4BC=12⇒BC=8 cm