Suppose, ABCD is the trapezium with AB=60, BC=26, CD=77, DA=25
Through B draw a line parallel to AD to meet DC at E. Clearly ABCD is a parallelogram
so BE=25, EC=DC-DE=17, BC=26
So by heron's formula we can find the area of BEC and its value will be 204
So the altitude BF through B of BEC will have length 2*204/17=24 cm
so the area of ABED is 24*60=1440
so the area of ABCD is 1440+204=1644

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