Question

Ile wynosi obwod kola o polu rownym 4 pi sm kwadratowych |?

Answer 1

P = πr²
πr² = 4πcm²
r² = 4 cm²
r = 2 cm

Ob= 2πr
Ob = 2×2×π
Ob = 4π
Ob = 12, 56cm

Answer 2

P=πr²
P=4πcm²
r=√P/π
r=√4πcm²/π=√4=2

ob=2πr
ob=2π×2=4π= 4×3,14=12,56