tolong bantu jawab yaaaa

R. lingkaran = s. kerucut
s = 15 cm

panjang busur = Keliling alas kerucut
216/360 x 2 x π x R = 2.π.r
3/5 x R = r
3/5 x 15 = r
r = 9 cm

t² = s² - r²
= 15² - 9²
= 225 - 81
= 144
t = √144
= 12 cm [D]