What is the area of this composite shape?

For this case what you should do is find the area of the rectangle and the are of the triangle.
 Area of the rectangle:
 A1 = (6) * (7)
 A1 = 42 in ^ 2
 Triangle area:
 A2 = (1/2) * (6-3) * (13-7)
 A2 = 9 in ^ 2
 The total area is the sum of both areas:
 A = A1 + A2
 A = 42 + 9
 A = 51 in ^ 2
 Answer
 the area of this composite shape is
 A = 51 in ^ 2