What is the difference between surface area and cross-sectional area?

Calculate the surface area of the solid shown in the figure excluding the bottom surface:

Quantity $1$: Area of square is $324 {\mathrm{cm}}^2$, whose perimeter is equal to perimeter of rectangle. Length of the rectangle is $4 \mathrm{cm}$ more than breadth of the rectangle. Find the area of rectangle.

Quantity $2$: $320 {\mathrm{cm}}^2$.

What are respectively the curved surface area and volume of a hemisphere of radius $21 \mathrm{cm}?$

(Take $\pi =\frac{22}{7}$)