Calculate the total surface area of a right circular cylinder with radius 4,cm and height 9,cm (use π=22/7). Give the answer to the nearest square centimetre.

Calculate the total surface area of a right circular cylinder with radius $4, cm$ and height $9, cm$ (use $π = \frac{22}{7}$ ). Give the answer to the nearest square centimetre.

medium 2 marks Class 10 · Mathematics · Surface Areas and Volumes

Answer

327 cm^{2}

The correct answer is $327 cm^{2}$ — Round to nearest integer: $327$ .

Total surface area of a cylinder: $T S A = 2 p i r (h + r)$ .
Substitute $r = 4$ cm, $h = 9$ cm: $T S A = 2 π \times 4 \times (9 + 4) = 8 π \times 13 = 104 π$ .
Replace $π$ with $\frac{22}{7}$ : $104 \times \frac{22}{7} = \frac{2288}{7} \approx 327.43$ .
Round to nearest integer: $327$ .

Common mistake: Forgetting to include top and bottom circles in the area

Concept tested: Cylinder surface area