Tolong bantu jawab dong pliss​

Jawaban:

a). jari jari lingkaran 10 cm, jika π = 3,14

•Keliling lingkaran :

K = 2πr

K = 2 × 3,14 × 10

K = 62,8 cm

•Luas lingkaran :

L = πr²

L = 3,14 × 10²

L = 3,14 × 100

L = 314 cm²

b). Jari jari lingkaran 21 cm, jika π = 22/7

•Keliling lingkaran :

K = 2πr

K = 2 × 22/7 × 21

K = 44 × 3

K = 132 cm

•Luas lingkaran :

L = πr²

L = 22/7 × 21²

L = 22/7 × 441

L = 22 × 63

L = 1.386 cm²