berapa keliling dan luasnya

luas=3,14XrXr
=3,14X20X20=1256
keliling=3,14Xd
=3,14X40=125,6

r = 20

k = 2 × π × r
= 2 × 3,14 × 20
= 125,6 cm

L = π × r²
= 3,14 × 20 × 20
= 1256 cm