Question

Radius of base of a cylinder is 25 cm and its height is 45 cm, find its curved surface area and total surface area. ( = 3.14)​

Answer 1

Given :

• Radius of Base (r) = 25cm

• Height (h) = 45cm

To find :

• Curved Surface area

• Total surface area

Solution :

Curved Surface area = 2πrh

➤ 2 × 3.14 × 25 × 45

➤ 2 × 3.14 × 1125

➤ 7065cm²

____________

Total surface area = 2πr(h + r)

➤ 2 × 22/7 × 25 (45 + 25)

➤ 2 × 22/7 × 25 × 70

➤ 11000cm²

____________

∴ CSA of cylinder is 7065cm²

TSA of cylinder is 11000cm²

____________

Answer 2

Given

=>Radius of base of cylinder 25cm

=>Height is 45cm

Find

=>The curved surface area..

=>Total surface area

By using formula

$\bold\orange{2 \ pi \ rh}$

Value of pi given 3.14

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Solution

=>Curved surface area=$\bold\pink{2 \ pi \ rh}$

=>Curved surface area=$\bold\blue{2×3.14×25×45}$

=>Curvee surface area=$\bold\red{2×3.14×1125}$

=>Curved surface area=$\bold\green{6.28×1125}$

=>Curved surface area=$\bold\purple{7065}$

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Now,

We will find the total surface area

By using formula

$\bold\orange{2 \ pi (h+r)}$

=>Total surface area=$\bold\pink{2 \ pi \ (h+r)}$

=>Total surface area=$\bold\blue{2 ×22/7×25(45+25)}$

=>Total surface area=$\bold\red{2×22/7×25(70)}$

=>Total surface area=$\bold\green{44/7×25×70}$

=>Total surface area=$\bold\purple{77000/7}$

=>Total surface area=$\ \boxed {\bf {11000 \ cm^2}}$