To find the surface area of the net diagram of the right circular cylinder, we need to calculate the surface area of the rectangle and the surface area of the two circles.
The surface area of the rectangle is given by:
Rectangle surface area = height x width = 9 inches x 20 inches = 180 square inches
The surface area of a circle is given by:
Circle surface area = π x radius^2 = 3.14 x 10^2 = 314 square inches
Since there are two circles attached to the rectangle, the total surface area of the two circles is 2 x 314 = 628 square inches.
Therefore, the total surface area of the net diagram of the right circular cylinder is 180 square inches (rectangle) + 628 square inches (circles) = 808 square inches.