A cone has a height of 4 cm4cm and its base has a radius of 6 cm6cm. If the cone is horizontally cut into two segments 2 cm2cm from the base, what would the surface area of the bottom segment be?

1 Answer
Oct 18, 2017

Total surface area of the bottom segment = 69.1382

Explanation:

Refer diagram below :
r = 3, r_2 = 3/2, h = 4, h_1 = 2,r=3,r2=32,h=4,h1=2,
l = sqrt(h^2+r^2) = sqrt(4^2+3^2) = 5l=h2+r2=42+32=5
l_1 = sqrt(h_1^2 + r_2^2) = sqrt(2^2+2^2) = 2sqrt2l1=h21+r22=22+22=22

Total surface area of the bottom segment
= pir^2 + pir_2^2 + pirl - pir_2l_1=πr2+πr22+πrlπr2l1
=pi3^2 + pi(3/2)^2 + pi*3*5 -pi*(3/2)*2sqrt2=π32+π(32)2+π35π(32)22
= 9pi + (9/4)pi + 15pi - 3sqrt2*pi=9π+(94)π+15π32π
69.1382 cm^269.1382cm2

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