The diameter of a cylinder is 28 cm and its height is 20 cm. Find its total surface are​

2 thoughts on “The diameter of a cylinder is 28 cm and its height is 20 cm. Find its total surface are​”

1. ✿ Question Given :

   • The diameter of a cylinder is 28 cm and its height is 20 cm. Find its total surface area.

   ✿ Find :

   • Total Surface Area.

   ✿ Required Solution :

   ★ Value Given to us :

   • Diameter of a Cylinder ➺ 28 cm
   • Height ➺ 20 cm

   ★ Formula Used Here :

   • Radius ➺ Diameter ÷ 2
   • Surface Area ➺ 2πr (h + r)

   ➻ First, we find Radius :

   So, We know –

   • Radius ➺ Diameter ÷ 2
   • Diameter ➺ 28 cm

   Radius ➙ 28 ÷ 2

   Radius ➙ 14 cm

   • Hence, the radius is 14 cm.

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   ➻ Now, we find Total Surface Area :

   So, We know –

   • Total Surface Area ➺ 2πr (h + r)
   • π ➺ 22/7
   • radius ➺ 14 cm
   • height ➺ 20 cm

   TSA ➙ 2 ༝ 22/7 ༝ 14 (20 + 14)

   TSA ➙ 2 ༝ 22/7 ༝ 14 ༝ 34

   TSA ➙ 88 ༝ 34

   TSA ➙ 2992

   Therefore,

   • Hence, the total surface area is 2992 cm².

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   @ItzRisingStaR

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2. Answer :

   Total surface area of cylinder = 2,992 cm²

   Given :

   • Diameter of the cylinder = 28 cm

   • Height of the cylinder = 20 cm

   To find :

   • Total surface area of the cylinder

   Concept :

   To calculate the total surface area of cylinder, firstly we will calculate the radius of the cylinder. After getting the value of the radius substitute the value of radius and height in the formula of TSA of cylinder. The resultant value will be the required answer.

   Knowledge Required :

   Formula to calculate radius, when diameter is given :

   • Diameter = Radius ÷ 2

   Formula to calculate total surface area of cylinder :

   • Total surface area of cylinder = 2πr(h + r)

   where,

   • Take π = 22/7

   • r denotes the radius of the cylinder

   • h denotes the height of the cylinder

   The commonly used units of area → cm², m², etc.

   Solution :

   Radius of the cylinder :

   ⠀⠀⠀⇒ Radius = Diameter ÷ 2

   ⠀⠀⠀⇒ Substituting the given values :

   ⠀⠀⠀⇒ Radius = 28 ÷ 2

   ⠀⠀⠀⇒ Radius = 14

   • Radius of the cylinder = 14 cm

   Total surface area of cylinder :

   ⠀⠀⠀⇒ TSA of cylinder = 2πr(h + r)

   ⠀⠀⠀⇒ Substituting the given values :

   ⠀⠀⠀⇒ TSA of cylinder = 2 × 22/7 × 14(20 + 14)

   ⠀⠀⠀⇒ TSA of cylinder = 2 × 22 × 2(20 + 14)

   ⠀⠀⠀⇒ TSA of cylinder = 44 × 2(20 + 14)

   ⠀⠀⠀⇒ TSA of cylinder = 44 × 2(34)

   ⠀⠀⠀⇒ TSA of cylinder = 2,992

   Total surface area of cylinder = 2,992 cm²

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