1
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Let's do this question if the radius of a cylinder is tripled, but it's called surface area is unchanged,

2
00:00:08,060 --> 00:00:10,270
then its height will be alright.

3
00:00:10,490 --> 00:00:13,410
So the radius is made three times the initial radius.

4
00:00:13,700 --> 00:00:17,050
Now you need to find the change in the height was the video.

5
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Give it a try and then let's do it together.

6
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All right.

7
00:00:20,300 --> 00:00:20,750
We are back.

8
00:00:20,780 --> 00:00:21,760
Let's do it together.

9
00:00:21,980 --> 00:00:23,940
So I draw a rough sketch over here.

10
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This is my cylinder now.

11
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The cold surface area is the natural surface area.

12
00:00:29,360 --> 00:00:29,780
Right.

13
00:00:29,790 --> 00:00:33,780
And we have seen that that is equal to two parts, OK.

14
00:00:34,010 --> 00:00:38,200
And over here, it's mentioned that the radius has become three times red.

15
00:00:38,480 --> 00:00:44,030
So the new cold surface area would be to buy into three hours into its dash.

16
00:00:44,360 --> 00:00:47,790
And over here, it's given that this and this is equal.

17
00:00:47,810 --> 00:00:48,860
So let's equate it.

18
00:00:49,070 --> 00:00:56,540
We get to periods is equal to buy into three are into it's right now to buy and to buy can be canceled

19
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over here and R and R can be canceled.

20
00:00:59,580 --> 00:01:05,060
So you get that each is equal to three X dash or each dash is equal to X by three.

21
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That is the height will become one third of the initial height.