berapa luas dan keliling lingkaran jika yang diarsir 3/4 dan jari jari nya 28 cm

Bab Lingkaran
Matematika SMP Kelas VI

luas = (3/4) x π x r x r
        = (3/4) x 22/7 x 28 x 28
        = 1848 cm²

keliling = (3/4) x 2 x π x r + 2 x r
            = (3/4) x 2 x 22/7 x 28 + 2 x 28
            = 132 + 56
            = 188 cm

Bab Bangun Datar

L = 3/4 × 22/7 × r^2
L = 3/4 × 22/7 × 28 × 28
L = 66/28 × 28 × 28
L = 66 × 28
L = 1.848 cm^2

K = 3/4 × 22/7 × d
K = 3/4 × 22/7 × 56
K = 66/28 × 56
K = 66 × 2
K = 132 cm