Please tolong bantu ya, aku gangerti no 7, 8,10, 11, 12

7. Keliling lingkaran = 2×π×r = 2×3,14×r = 37,68
6,28×r = 37,68
r = 37,68/6,28 = 6
Jari-jari = 6, maka diameter = 6×2 = 12 cm .

10. Keliling lingkaran = 2×π×r = 2×3,14×r = 132 cm
6,28×r = 132
r = 132/6,28 = 21,01 .
Luas = π×r² = 3,14×21,01×21,01 = 1.386 .