tolong nomor 46 dan 47

26.
Panjang juring
210/360 × 2 phi x 18
= 7 / 12 × 36 phi
= 21 phi

panjang jari2 baru
2 phi r = 21 phi
r = 21/2 = 10,5 cm (D)

27.
Panjang juring
= 3/5 × 2 × phi × 20
= 24 phi

panjang jari2 baru
2 phi r = 24 phi
r = 24/2 = 12 cm

tinggi kerucut
t^2 = 20^2 - 12^2 = 400 - 144 = 256
t = 16 cm (D)