1) S = 4πr²1296π = 4πr²r² = 1296π / 4r² = 324πr = √(324π)r ≈ 18 дм
2) S = 4πr²6,25π = 4πr²r² = 6,25π / 4r² = 1,5625πr = √(1,5625π)r ≈ 1,25 м
1) S = 4πr²
1296π = 4πr²
r² = 1296π / 4
r² = 324π
r = √(324π)
r ≈ 18 дм
2) S = 4πr²
6,25π = 4πr²
r² = 6,25π / 4
r² = 1,5625π
r = √(1,5625π)
r ≈ 1,25 м