The base of cylinder is B=64πcm2. Find the surface area of the cylinder if its height is 3 times bigger than the radius.
B=64πcm2
R=64 (not sure)
H=192
S=? S=2Rπ(R+H)
S=2x 64π(64+192)
S=128π x 256
S=32768π
S=102943.70
Is this math problem solved right?
2016-05-27 4:26 pm
回答 (3)
2016-05-27 4:40 pm
Base area :
π × R² = 64π cm²
R² = 64 cm²
R = 8 cm
Height of the cylinder, h
= 3R
= 3 × 8 cm
= 24 cm
The surface area of the cylinder
= 2B + 2 × π × R × h
= (2 × 64π + 2 × π × 8 × 24) cm²
= 512π cm²
≈ 512 × 3.14 cm²
= 1607.68 cm²
π × R² = 64π cm²
R² = 64 cm²
R = 8 cm
Height of the cylinder, h
= 3R
= 3 × 8 cm
= 24 cm
The surface area of the cylinder
= 2B + 2 × π × R × h
= (2 × 64π + 2 × π × 8 × 24) cm²
= 512π cm²
≈ 512 × 3.14 cm²
= 1607.68 cm²
2016-05-27 4:39 pm
No it is not.
r = 8 not 64
than follow the rest you did
r = 8 not 64
than follow the rest you did
參考: Socrates Tutoring
2016-05-27 4:38 pm
No. You can't just make up a number for r. SOLVE FOR IT.
So B = pi*r^2 = 64 pi
Solve that for r. The answer is not 64.
Then proceed as you did.
So B = pi*r^2 = 64 pi
Solve that for r. The answer is not 64.
Then proceed as you did.
收錄日期: 2021-04-18 14:52:15
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