jika luas bangun tersebut 462 cm^2, kelilingnya adalah

L = 3/4 phi × r^2
462 cm^2 = 3/4 22/7 × r^2
462 cm^2 × 4/3 × 7/22 = r^2
196 cm^2 = r^2
r = akar 196
r = 14 cm

K = 3/4 × 2 × phi × r
=3/4 × 2 × 22/7 × 14 cm
= 3/4 × 88 cm
= 66 cm

=> Jawaban B