Odpowiedź :
d=20cm
H=8cm
P=TTr²×H
P=TT ×20cm²×8
P=3×400×8
P=9 600 cm²
odp. pole walca wynosi 9 600 cm²
H=8cm
P=TTr²×H
P=TT ×20cm²×8
P=3×400×8
P=9 600 cm²
odp. pole walca wynosi 9 600 cm²
Podstawa, 2r
20 ² = 8 ² + x²
x² + 64 = 400 / -64
x² = 336
x = √336
x = 4√21
Pc = 2* Pp + Pb = 2 * πr² + 4√21 * 8 ≈ 2 * 3,14 * (4√21)² + 4√21 * 8 = 6,28 * 336 + 32√21 = 2110,08 + 32√21 (cm²)
20 ² = 8 ² + x²
x² + 64 = 400 / -64
x² = 336
x = √336
x = 4√21
Pc = 2* Pp + Pb = 2 * πr² + 4√21 * 8 ≈ 2 * 3,14 * (4√21)² + 4√21 * 8 = 6,28 * 336 + 32√21 = 2110,08 + 32√21 (cm²)