Question

The radius of a cone is 5 cm and height is 12 cm.
Find the curved surface area of cone.​

Answer 1

surface area= 204.28 cm^2

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I hope that it will be helpful for you

Answer 2

Diagram :-

$\setlength{\unitlength}{1.2mm}\begin{picture}(5,5)\thicklines\put(0,0){\qbezier(1,0)(12,3)(24,0)\qbezier(1,0)(-2,-1)(1,-2)\qbezier(24,0)(27,-1)(24,-2)\qbezier(1,-2)(12,-5)(24,-2)}\put(-0.5,-1){\line(1,2){13}}\put(25.5,-1){\line(-1,2){13}}\multiput(12.5,-1)(2,0){7}{\line(1,0){1}}\multiput(12.5,-1)(0,4){7}{\line(0,1){2}}\put(18,1.6){\sf{r}}\put(9.5,10){\sf{h}}\end{picture}$

Given :-

• Radius of cone = 5 cm
• Height of cone = 12 cm

To Find :-

• Curved Surface Area of cone = ?

Answer :-

• Curved Surface Area of cone = 204.2 cm²

Explaination :-

First we have to calculate the Slant Height of the cone :

➝ Slant Height = √(Radius)² + (Height)²

➝ Slant Height = √(5)² + (12)²

➝ Slant Height = √25 + 144

➝ Slant Height = √169

➝ Slant Height = 13 cm

Hence,the slant height of the cone is 13 cm.

Now, let's find the CSA of cone :

➻ CSA of cone = πrl

➻ CSA of cone = 22/7 × 5 × 13

➻ CSA of cone = 204.2 cm²

Therefore, Curved Surface Area of cone is 204.2 cm².