The exterior of a solid cone is painted. The height of the cone is 11.4 centimeters, and the diameter of its opening is 5 centim
2 answers:
Answer:
111 cm^2
Step-by-step explanation:
h = 11.4
d = 5 so r (radius) = 2.5
Surface Area of a Cone Formula: πr^2 + πrs
s represents the slant height of the cone, lets represent this with a drawing.
We have the values of h and r, but we don't have the value of s, meaning we have to find it. We can do this by using pythagorean theorem.
a^2 + b^2 = c^2
These three values can come together to create a right triangle which we can seperate from the rest of the diagram, now we can find s.
s = √(11.4^2 + 2.5^2) so s = 11.67
now that we have all of the pieces, we can plug back into the original surface area formula. πr^2 + πrs
π(2.5^2) + π(2.5)(11.67) = 111.29 cm^2 or 111 cm^2
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