Answer:
84 cm^2
Explanation:
Let, the area be A.
Extend the 11cm line to the right upto the 9cm line. Then we will get a rectangle at the bottom and a trapezium on the top.
Then, A = Rectangle + Trapezium
= ( 3 * 18 ) + { ( 1/2 ) * ( ( 18 - 11 ) + 3 ) * ( 9 - 3 ) }
= 54 + 30
= 84
[If there's any mistake, please inform me]