A lamina DDD is the triangle with vertices (0,0),(1,0),(0,1)(0,0), (1,0), (0,1)(0,0),(1,0),(0,1). Find ∬D1dA\iint_D 1 dA∬D1dA.
12\frac{1}{2}21
111
14\frac{1}{4}41
222