To make this a fraction, let's put

. We can divide both top and bottom by 6, leaving us with

. This is as far as we can reduce it, making it your answer. I hope this helps!
Firstly, we will draw figure
now, we will draw a altitude from B to DC that divides trapezium into rectangle and right triangle
because of opposite sides of rectangle ABMD are congruent
so,
DM=AB=9
CM=CD-DM
CM=18-9
CM=9
now, we can find BM by using Pythagoras theorem

now, we can plug values
we get


now, we can find area of trapezium

now, we can plug values
and we get


so, area of of the trapezoid is
..........Answer