Please help me with this work

Acircle has a circumference of 2 pi cm. which statement about the circumference and area is true? a comparison of the area and circumference is not possible since the area cannot be determined. the numerical values of the circumference and area of the circle are equal. the numerical value of the circumference is greater than the numerical value of the area. the numerical value of the circumference is less than the numerical value of the area.

The distance from the sun to earth is about 1.5×10 to the 11th m suppose light travels at a speed of 3×10 to the 8th m per second about how long does it take light from sun to reach earth

The area (in square feet) of an x-foot-wide sidewalk can be modeled by y=-0.002x^2+0.006x.what is the width of the sidewalk to the nearest foot?