Question

A cylinder has a height of 4.5 cm and a diameter of 1.5 cm. What is the surface area of the cylinder in square centimeters? Use 3.14 for pi. A.21.2 B.24.7 C.7.9 D.31.8

Answer 1

A = 56.5cm²

Explanation:

r = 1.5cm

h = 4.5cm

A=2πrh+2πr2

A = 2πr(h+r)

A = 2 x 3.14 x 1.5 x ( 4.5 + 1.5 )

A = 56.62cm²

Answer 2

`\large{ \underline{ \underline{ \bf{ \red{Given}}}}}`

• Height of the cylinder = 4.5 cm
• Diameter of the cylinder = 1.5 cm
• Consider π = 3.14

`\large{ \underline{ \underline{ \bf{ \purple{To \: find}}}}}`

• Surface area of the cylinder in cm²?

`\large{ \underline{ \underline{ \bf{ \green{Now, \: What \: to \: do?}}}}}`

For solving this question, we should know how to calculate the surface area of cylinder i.e Total surface are of cylinder = 2πr(r + h)

Where, r = radius of the cylinder and h is the height of the cylinder.

`\large{ \bf{ \underline{ \underline{ \blue{Solution}}}}}`

We are provided with,

• h = 4.5 cm
• d = 1.5 cm

Then, Radius = 1.5 cm / 2

By using formula,

⇛ 2πr(r + h)

⇛ 2 × 3.14 × 1.5/2 (1.5/2 + 4.5) cm²

⇛ 2 × 3.14 × 3/4( 5.25) cm²

⇛ 24.7275 cm²

❇ Option B

✤ TSA of the cylinder = 24.7275 cm²

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