Q1 of 25 Page 9

ABCD is a parallelogram, AE ⊥ DC and CF ⊥ AD. If AB=18 cm, AE=9 cm and CF=10 cm, find AD.


Given that,


In a parallelogram ABCD:


CD = AB = 16cm (Opposite sides of parallelogram are equal)


We know that,


Area of parallelogram = Base × Corresponding altitude
As AE ⊥ DC,


Area of parallelogram ABCD = CD × AE …. (1)


Also, CF ⊥ AD,


Area of parallelogram ABCD = AD × CF …... (2)


From (1) and (2),


CD× AE = AD × CF


18 cm × 9 cm = AD × 10 cm




AD = 16.2 cm


Hence the value of AD is 16.2 cm.


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