pakai caranya! (kerucut) Diketahui = jari2 ⭕ atas =7cm Jari2 ⭕ bawah =14 cm Garis pelukis =25 cm

Gunakan kesebangunan cari garis pelukis kerucut kecil

S/(s+25) = 7/14
s×14 = 7× ( s+25)
14 s = 7s+175
7s= 175
S= 25

Luas kap lampu

= Selimut kerucut besar - selimut kerucut kecil
= phi ×r×s - phi ×r×s
= phi ×14 ×50 - phi × 7×25
= phi ( 700 - 175)
= phi × 525
= 22/7 × 525
= 22× 75
= 1650