



 
Hi Ana, Without the diagram this is difficult. I can guess what the diagram looks like but I think there is a piece of information missing. Penny Ana wrote back.
You still didn't send a diagram so the best I can do is guess. I think the diagram looks something like this. I want to find the area of the sector $ABC$ and to do so I am going to use the symmetry of the circle. The area of the sector $ABC$ is a fraction of the area of the circle of radius 40 ft. The length of the arc $AB$ is a fraction of the circumference of the circle of radius 40 ft. By the symmetry of the circle these two fractions are the same. Thus \[\frac{\mbox{area of the arc ABC}}{\pi \; 40^2} = \frac{78.21}{2 \pi \; 40}\] and hence \[\mbox{area of the arc ABC} = \frac{78.21}{2 \pi \; 40} \times \pi \; 40^2 = 156.24 \mbox{ square feet.}\] Do you know the depth of Julie's lot, the distance $d$ in my diagram? If so you can use the procedure I used above to find the area of the sector $DEC,$ and then the area of Julie's lot is the difference in the areas of the two sectors. I hope this helps, Penny  


Math Central is supported by the University of Regina and the Imperial Oil Foundation. 