Jawabanmu

2014-05-30T13:51:32+07:00
AB = 12,56 maka r = 2 cm
Luas juring = 40/360 . 3,14 . 4 = 1,395
2014-05-30T13:56:54+07:00
12,56=40/360×3,14×2×r. 12,56=1/9×6,28r. 113,04=6,28r. r=18cm. luas juring=40/360×phi×r^2=1/9×3,14×18×18=3,14×2×18=113,04cm kuadrat