cari luas dan kelilingnya ya... pakai cara

L= π×r×r = 22/7×21×21 = 1386 cm
k= π×d = 22/7×42 = 132 cm

Lo = π.r.r
= 22/7.21.21
= 22/7.441
= 1386 cm2
Ko = π.d
= 22/7.42
= 132cm