



 
Hi Jone, If the dome is a hemisphere and its height is 20 m then the radius of the dome is 20 m. The floor is then a circular disk of radius 20 m. What is the areas of the floor in meters squared? It takes 5 gallons of paint to paint the floor so divide 5 gallons by the area of the floor to find the coverage of the paint in gallons per square meter. The surface area of a sphere is 4 π r^{2}, where r is the radius and hence the surface area of a hemisphere is half this quantity. What is the surface area of a hemisphere of radius 20 meters? You know the coverage of the paint is gallons per square meter so how many gallons will it take to paint the hemisphere? Penny  


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