1 mile=5280 feet
5 miles=5 times 5280=26400 ft
It would be the mass divided by the volume
the equation is d = m/v from what i remember
It's 21 square units. If you map it on a complex plane (x-axis is real numbers, y-axis is imaginary numbers) you'll see that the sides of the rectangle is 3 and 7 which multiply to 21.
The perimeter would probably be 292 because at+b is 7(9)+10, or 73 and there are 4 sides of a circle, so 73 times 4 is 292.