Question

HITUNGLAH KELILING DAN LUAS LINGKARAN JIKA DIKETAHUI
A.JARI JARI 21 CM
B.DIAMETER 40 CM

Answer 1

Keliling A
K = 2 x π x r
K = 2 x 22/7 x 21
K = 2 x 22 x 3
K = 132 cm

Keliling B
K = π x d
K = 3,14 x 40
K = 125,6 cm

Luas A
L = π x r²
L = 22/7 x 21²
L = 22/7 x 441
L = 22 x 63
L = 1386 cm²

Luas B
L = π x (d:2)²
L = 3,14 x (40 : 2)²
L = 3,14 x 20²
L = 3,14 x 400
L = 1256 cm²

Answer 2

A. r = 21 cm
    K = 2*π*r
        = 2*22/7*21
        = 44*3
        = 132 cm
    L = π*r²
       = 22/7*21*21
       = 66*21
       = 1386 cm²

b. d=40 cm
    K = π*d
        = 3.14*40
        = 125.6 cm
     L = π*r²
         = 3.14 * 20 * 20
         = 1256 cm²

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