Need asap quick square root sum question ! i think my answers wrong check

Maria walks a round trip of 0.75 mile to school every day. how many miles will she walk in 4.5 days

Circle a has a diameter of 7 inches, a circumference of 21.98 inches, and an area of 38.465 square inches. the diameter of circle b is 6 inches, the circumference is 18.84 inches, and the area is 28.26 square inches. part a: using the formula for circumference, solve for the value of pi for each circle. (4 points) part b: use the formula for area and solve for the value of pi for each circle. (4 points)

Ineed to know how to write question one in mathematical terms