r=21 phi=22/7 tentukan keliling dan luas lingkaran berikut

K = 2 x π x r
K = 2 x 22/7 x 21
K = 2 x 22 x ( 21 ÷ 7 )
K = 44 x 3
K = 132 cm

L = π x r²
L = 22/7 x 21 x 21
L = 22 x 3 x 21
L = 66 x 21
L = 1.386 cm²

Semoga Bermanfaat

keliling = 22/7 x 42 = 132
luas = 22/7 x 21 x 21 =1386