Picture a ball traveling at a constant speed around the inside of a circular structure. is the ball accelerating? explain

Yes. On a circular path, the direction of motion is constantly changing. Change of direction is acceleration, even at constant speed.

Initially looks confusing because the shape is bent, but if you imaging opening a card then it is just a rectangle.
in terms of the lengths, if the card closes then the "bent" lines must be the same length as the straight lines.  the 7in. is there to confuse you.
the total area is just 5x4 for one half of the card, then another 5x4 for the "bent bit".
answer: c: 40 square inches.