The parallel sides of a trapezium is 77 m and 60 m and its non-parallel sides are 26 m and 25 m. Find the area of the trapezium.

Let ABCD be a trapezium in which
AB = 60 m,  CD = 77 m,  BC = 26 m,  AD = 25 m
and
Draw BE || to AD
Thus ABED is parallelogram 
Hence AB = DE = 60 m.
AD = BE = 25 m
and EC = DC - DE = 77 - 60 = 17 m
and
Now in ΔBEC,
BE = 25 m, BC = 26m, EC = 17m
Let the height of B from EC be = h m
S =  = 34
Area of ΔBEC =
 ´ EC ´ h =
⇒  ´ 17 ´ h =
or h = 24 m.
Now area of trapezium = (sum of parallel sides) × height
\\ Area of trapezium = (60 + 77) ´ 24 = 1644 m².