Answer:
52.5 cm^2
Step-by-step explanation:
The base length of the triangle on top is ...
8 cm - 1 cm - 2 cm = 5 cm
Then the area of that triangle is given by the formula ...
A = (1/2)bh = (1/2)(5 cm)(5 cm) = 12.5 cm^2
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The area of the rectangle below that triangle is the product of its length and width:
A = (8 cm)(5 cm) = 40 cm^2
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The total area is the sum of the areas of the rectangle and triangle, so is ...
total area = 40 cm^2 + 12.5 cm^2 = 52.5 cm^2
is the boundary of the triangle 
, then by Green's theorem
