Question

can anyone help?

Find the surface area of a cone with a diameter of 12 cm and a height of 8 cm. Use pi = 3.14. Show your work for credit.

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Answer 1

1. SA(Surface area of a cone) = [circular base area] + [lateral surface area] = pi*r² + pi*r*s
s is the slant height. you already know pi = 3.14, radius = 6(because, diameter =12)
you need to find the slant height. the radius and the height make the right angle.
so, (slant height)² = (radius)² + (height)² = 6² + 8² = 36+64 = 100=10^2
now, pi =3.14, r=6, s=10
SA = (3.14*6²) + (3.14*6*10)