Shown below is a cuboid of dimensions 4 cm × 6 cm × 8 cm. The cuboid is split into two identical wedges by a plane perpendicular to AEFB, along its diagonal, as shown below.

The surface area of one of the wedges is sq cm.

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