Tentukan luas lingkaran dan keliling lingkaran jika diketahui jari-jari = 30 cm Diameter 42 cm dengan caranya

Luas = πr² , r = 30cm
= 3,14 x (30)²
= 3,14 x 900
= 2826cm²
Keliling = πd , d = 42cm
= 22/7 x 42
= 132cm

r = 30 cm
Luas lingkaran
= πr²
= 3,14 × 30 cm × 30 cm
= 2.826 cm²
Keliling lingkaran
= 2πr
= 2×3,14×30 cm
= 188,4 cm


Diameter = 42 cm , r = 21 cm
Luas lingkaran
= πr²
= 22/7 × 21 cm × 21 cm
= 1.386 cm²
Keliling lingkaran
= πd
= 22/7 × 42 cm
= 132 cm