Remark
You can get it just by looking at the net. It has 6 squares. Each square has a side of 5 cm by 5cm. Find the area of 1 square and multiply by 6.
Step One
Find the area of one square.
Formula
Area = s^2
Solve
Area for 1 square = s^2 = 5^2 = 25 cm^2
Step Two
Find the area for six squares.
Area of the net = 6*Area of one square = 6 * s^2
6*s^2 = 6 * 25
Area = 150 cm^2