h. L = 4πr²
L = 4π(5)²
L = 4π(25)
L = 100π m²
i. L = 4πr²
L = 4π(8)²
L = 4π(64)
L = 256π dm²
j. L = 2πr (r + t)
* t = √(15² - 12²)
t = √(225 - 144)
t = √81 = 9 m
L = 2π x 6 (6 + 9)
L = 12π (15)
L = 180π
k. L = πr (r + s)
* s = √(t² + r²)
s = √(9² + 6²)
s = √(81 + 36)
s = √117 = 10,82 dm
L = π x r (r + s)
L = π x 6 (6 + 10,82)
L = 6π (16,82)
L = 100,92π dm²