Answer:
42 cm^2
Explanation:
Please find attached an image showing the diagram
area of shaded part = area of larger rectangle - area of smaller rectangle
Area of a rectangle = length x width
larger rectangle = 10 x 7 = 70 cm^2
smaller rectangle = 7 x 4 = 28cm^2
Area of shaded part : 70 - 28 = 42cm^2