Your town is building a circular ice rink with a diameter of 100 feet. Around the ice rink will be a walkway that is 10 feet wide. What is the approximate area of the walkway?

One way is

area of total=walkway+rink

walkway=area of total-rink

area=pir^2

diameter=2r

d/2=r

rink is diameter 100

d=100

100/2=50=r

area=pi50^2

area=pi2500

area of rink

diameer=100+10+10 (because the walkway is on both sides)

120/2=60

area=pi60^2

area=360pi

total-rink=250pi-360pi=110pi

if aprox pi=3.14 then

area=345.4 ft^2