1.jari-jarinya 4cm=diameternya…….=kelilingnya……..=luasnya…….

1. r = 4
diameter = 2 *4 = 8
kelliling = 3,14 * 8 = 25,12 cm
luas = 3.14 * 4 * 4 = 50,24 cm^

2. r = 21
d = 2 * 21 =42
keliling = 22/7 * 42 = 132 cm
luas = 22/7 * 21 * 21 = 1386 cm^
3. d = 50
r = 50 / 2 = 25
keliling = 3,14 * 50 = 157 cm
luas = 3,14 * 25* 25 = 1962,5 cm^

1.diameternya = 8,kelilingnya = 25,12.luasnya = 50,24
2.diameternya = 42,kelilingya = 132,luasnya = 1386
3.jari-jarinya = 25,kelilingnya = 78,5.luasnya = 1962,5