You can have a lot of ways to solve this problem, but I'm going for solving for the lawn's area directly instead of solving the reserved section and subtracting it from the total area of the whole place.
First, cut the lawn so that it becomes two shapes: a rectangle, and a triangle. Solve for both areas.
A(r) = lw
A(r) = (14)(16)
A(r) = 224 square feet
A(t) = bh/2
A(t) = (8)(14) / 2
A(t) = 112 / 2
A(t) = 56 square feet
Add the two areas:
A(r) + A(t) = Area of lawn
224 square feet + 56 square feet = 280 square feet.
The area of the lawn, therefores, is 280 ft^2.
