+1 How many square feet of concrete surface are there in a circular walkway 8ft wide surrounding a tree if the tree has a diameter of 3 ft (round to the tenths place.)
+129839 This si just the difference in area of two circles......the larger one has a radius of 9.5 [the radius of the tree = 1.5 ft plus the 8 foot radius of the sidewalk ]....and the smaller one has a radius of 1.5 ft = the radius of the tree...so....the area of the sidewalk =
pi ( 9.5^2 - 1.5^2) ≈ 276.5 sq ft
Here's a pic of the situation :
AB is the radius of the tree = 1.5 ft .....BC is the with of the sidewalk = 8 ft
