For this problem, let's think of this shape as a rectangle and a triangle put together. We'll calculate the area of each shape and add them together to get the total area.
For the rectangle, the equation is b*h. Here the base = 7 cm and the h = 4cm
For the triangle, the equation is 1/2 * (b*h). Here the base is a little tricky to find. We know the total length is 12cm and the rectangle length was 7cm. So 12-7= 5cm, which is the base of the triangle. The height would be the same (4cm).
Once you calculate those two areas and add them up, you'll have the total area of this shape.