Question 893993

A water tank has the shape of a cone with the vertex down. The tank is 10 m high and has a base radius of 3 m. When the water in the tank is 5 m deep, what is the area of the surface of the water at that instant? (Hint: make a sketch and set up similar triangles.)
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Diameter of circular top of water at the 5m mark of cone = 3 m, or radius of: {{{3/2}}}, or 1.5m
Area of surface of water at the 5m mark: {{{pi*r^2}}}, or {{{pi * 1.5^2}}}, or {{{2.25*pi}}}, or {{{highlight_green(7.068583471m^2)}}}