The area of a trapezoid is (a+b)/2 * h
a is the length of the small base which is the one on the top and is 4cm
b is the length of the big base which is the one at the bottom and is 4 + 3 + 3 = 10cm
h is the height which is 7cm
So the area is (4+10)/2 * 7
A= 14/2 * 7
A= 7 * 7
A= 49 cm^2