This math question i really dont get.. A city park contains a cylindrical artificial pond that has a radius of 7.5 m. A 2 m concrete deck will be constructed around the pond. The concrete should be at least 15 cm thick. Calculate the minimum volume of concrete required to construct the deck, to one decimal place. Draw a diagram.
diagram below ok so what you do is find area of total-areapond=areaaround then times that by the height areatotal=pir^2 r=7.5+2=9.5 aeratotal=pi9.5^2=90.25pi areapond=pi7.5^2=56.25pi areaaround=90.25pi-56.25pi=34pi volume=area times height 34pi m^2 15 cm thick convert 15cm to m 0.15m 34pi times 0.15=5.1pim^3=16.02m^3 volume=16.0 m^3 if converted to cm v=16022122.5 cm^3