Maude's living room is in the shape of a rectangle. its dimensions are 21 feet by 14 feet. find the length of the diagonal of the living room. round your answer to the nearest tenth if necessary.

Martha is training for a duathlon, which includes biking and running. she knows that yesterday she covered a total distance of over 55.5 miles in more than than 4.5 hours of training. martha runs at a speed of 6 mph and bikes at a rate of 15.5 mph.