Matematika

Pertanyaan

*PR*
Diketahui:
Keliling : 132 cm
Jari-jari : ?
Luas : ?

2 Jawaban

  • d = kell. : Π = 132 : 22/7 = 42cm
    jawab =
    r = d : 2 = 42 : 2 = 21cm
    luas = Π × r² = 22/7 × 21² = 22/7 × 441 = 1386cm²
  • Keliling lingkaran = phi × d
    132 = 22/7 × d
    d = 132 × 7/22
    d = 6 × 7
    d = 42

    Jika d = 42 itu artinya r = 1/2 × 42 = 21 cm

    Luas lingkaran = phi × r^2
    = 22/7 × (21)^2
    = 22/7 × 441
    = 22 × 63
    = 1.386 cm^2

    Semoga membantu :)

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