On my homework it says "find the missing dimension of the circle," so if the circumference is 43.5 inches, the diameter is my teachers didn't explain this very well and i'm pretty confused.

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.

Tom drove 206 miles in 3.9 hours. estimate his average speed.

The perimeter of a rectangular rug is 24 feet. the length of the rug is 1 2/5 i s width. what is the area of the rug