Jawabanmu

2014-09-09T20:53:08+07:00
⇔v tabung = πr²t
⇔42.390 = 3,14.r².15
⇔42.390 = 47,1.r²
⇔42.390:47,1 = r²
⇔900 = r²
⇔√900 = r
⇔30 = r ⇒ jari jari alas tabung

luas alas tabung = π.r²
= 3,14 30.30
= 2826

luas selimut tabung = 2πrt
= 2.3,14.30.15
= 2826

coba diteliti lagi yaa :)