ABCD is a trapezium in which AB||DC. M and N are the mid-points of AD and BC respectively, If AB=12cm, MN=14 cm, then CD=

Construction: Join A to C

Mark the intersection point of AC and MN as O


Now, M and N are mid points of the non-parallel of a trapezium


Therefore,


MN || AB || DC


So,


MO || BC


And,


M is a mid-point of AD


Therefore,


MO= BC


Similarly,


NO = AB


Therefore,


MN = MO + NO


= (AB + CD)


But,


MN = 14 cm


Hence,


(AB + CD) = 14 cm


12 + CD = 28


CD = 16 cm

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