Tolong bantu dijawab sama caranya ya ​

Jawaban:

a.

K = 2 × π × r

628 = 2 × 3,14 × r

628 = 6,28r

r = 628 / 6,28

r = 100 cm

b.

K = 2 × π × r

50 = 2 × 3,14 × r

50 = 6,28r

r = 50 / 6,28

r = 7,96 cm

c.

K = 2 × π × r

132 = 2 × 3,14 × r

132 = 6,28r

r = 132/6,28

r = 21,36 cm