Let's represent the area of the lawn with "x" (in square meters).
Maria charged $135 plus $9.55 per square meter, so her total earnings can be expressed as:
Total earnings = $135 + $9.55 x
We know that Maria was paid $1854, so we can set up an equation and solve for x:
$1854 = $135 + $9.55 x
Subtracting $135 from both sides:
$1719 = $9.55 x
Dividing both sides by $9.55:
x = 180
Therefore, the area of the lawn is 180 square meters.