So the image consists of 1 rectangle and half a circle.
Rectangle - 12*19 = 228Half a circle - [tex] \pi r^2 = \pi 6^2 = 36 \pi /2 = 18 \pi [/tex]
In the end there are 2 rectangles (2*228 = 456) and 1 full circle (18*2 = 36), which makes the shaded area 456ft and 36[tex] \pi [/tex]