Question

Dik : perbandingan r : s = 4 : 5 jika luas selimut kerucut 180♊ cm*kubik maka luas alas kerucut adalah ??

Answer 1

R : s = 4 : 5
r = 4x dan s = 5x
luas selimut = π r s = 180 π
20 x² = 180
x = 3
r = 4x = 12
luas alas = π r^2 = π(12^2) = 144 π = 452,16