Step-by-step explanation:
I'll leave the drawing part to you. However, you just have to note that if each of the tile is 1/2 ft, the height should be 5 squares and the width is 9 squares. The area of the section of the wall is calculated by multiplying the height and the width.
A = H x W = (2 1/2 ft) x (4 1/2 ft) = 11.25 ft²
