Question 864906
The picture gives you slant height and diameter.  If s is slant height, d is diameter, r is radius, the if you lookup the formula for surface area of a cone using your Geometry book, this is {{{pi*r*s}}}; which EXCLUDES the area of the circular base. 


Your picture is of two such cones sharing a circular base, so for your picutre, surface area is {{{2*r*s*(pi)}}}
{{{highlight(2*(12/2)10*(pi))}}}


Formula for volume of a cone is {{{v=(1/3)pi*x*r^2}}}; just be aware, you have two of these stuck together in your picture.  You can find h using pythagorean theorem.  {{{h^2=x^2+(d/2)^2}}}; and you already have d=12, h=10, and you can find x which is the HEIGHT of each cone, meaning from center of base to the cone tip.  Do <b>NOT</b> confuse this height with "SLANT HEIGHT".  
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Also see very very carefully, I am using "x" for cone height.  h is for slant height here.  (I'm using slightly different variables for surface area than for volume).