Jawab:

a. jari jari 7 cm, diameter 14 cm

b. jari jari 21 cm, diameter 42 cm

c. jari jari 20 cm, diameter 40  cm

d. jari jari 17,5 cm, diameter 35 cm

e. jari jari 50 cm, diameter 100 cm

f. jari jari 140 cm, diameter 280 cm

Penjelasan dengan langkah-langkah:

a. Keliling = 44 cm

K = 2 × π × r

44 = 2 × × r

44 =   × r

44 × 7 = 44 × r

7 = r

d = 2 × r

d = 2 × 7

d = 14

b. Keliling = 132 cm

K = 2 × π × r

132 = 2 × × r

132 =   × r

132 × 7 = 44 × r

924 = 44 × r

21 = r

d = 2 × r

d = 2 × 21

d = 42

c. Keliling = 125,6 cm (π = 3,14)

K = 2 × π × r

125,6 = 2 × 3,14 × r

125,6 = 6,28 × r

20 = r

d = 2 × r

d = 2 × 20

d = 40

d. Keliling = 110 cm

K = 2 × π × r

110 = 2 × × r

110 =   × r

110 × 7 = 44 × r

770 = 44 × r

17,5 = r

d = 2 × r

d = 2 × 17,5

d = 35

e. Keliling = 314 cm (π = 3,14)

K = 2 × π × r

314 = 2 × 3,14 × r

314 = 6,28 × r

50 = r

d = 2 × r

d = 2 × 50

d = 100

f. Keliling = 880 cm

K = 2 × π × r

880 = 2 × × r

880 =   × r

880 × 7 = 44 × r

6160 = 44 × r

140 = r

d = 2 × r

d = 2 × 140

d = 280