diketahui luas selimut tabung 1.408cm2, jika tinggi tabung 28 cm, maka diameter alasnya adalah

Luas selimut tabung = 2 × phi × r × t
@ 1408 = 2 × 22/7 × r × 28
@ 1408 = 56 × 22/7 × r
@ 1408 × 7/22 = 56 × r
@ 448 = 56 × r
@ r = 448/56
@ r = 8cm > d = 2r = 2(8) = 16cm

Semoga membantu.. ^_^

semoga membantu
Maaf kalo salah