diameter alas kerucut 20 cm,sedangkan tingginya 24 cm.luas seluruh permukaan sisi kerucut adalah

lp kerucut = phi.r(r+s)

=3,14.10(10+[24²-10²])
31,4.10+√576-100
31,4.10+21,8
31,4.31,8
=998,52

r = 1/2d
r = 1/2.20
r = 10 cm
π = 3,14

S² = r²+t²
S² = 10²+ 24²
S² = 100+ 576
S² = 676
S = √676
S = 26 cm
Jwb =
Lpk = πr(r+s)
Lpk = 3,14.10(10+26)
Lpk = 31,4(36)
Lpk = 1130,4 cm²