1
00:00:00,730 --> 00:00:07,780
Let's do this question, the parallel sides of a trapezius are 40 centimetre and 20 centimeter if it's

2
00:00:07,780 --> 00:00:14,980
nonpolluting, sides are both equal and each being 26 centimeter, find the area of the trapezius.

3
00:00:15,160 --> 00:00:15,610
All right.

4
00:00:15,830 --> 00:00:19,010
All the video, give it a try and then let's do it together.

5
00:00:19,390 --> 00:00:19,990
All right.

6
00:00:20,200 --> 00:00:21,470
Now let's do it together.

7
00:00:21,610 --> 00:00:27,110
Let's drop the perpendicular from A and B. That's AP and B Q over here.

8
00:00:28,000 --> 00:00:30,970
Now let's mark the information that is given to us.

9
00:00:31,270 --> 00:00:39,330
We know a B is equal to 20 and this is 40, and these two non sides are equal to 26 centimeters.

10
00:00:39,340 --> 00:00:40,090
So that's given.

11
00:00:40,360 --> 00:00:42,880
Now therefore, P Q also will be 20.

12
00:00:42,880 --> 00:00:43,230
Right.

13
00:00:43,450 --> 00:00:49,660
And let this be X and then this also will be X because we are dealing with an isosceles trapezius because

14
00:00:49,660 --> 00:00:51,700
these two sides are equal.

15
00:00:52,060 --> 00:00:55,190
So this is also X, this is also X and this is 20.

16
00:00:55,420 --> 00:01:00,180
Now you can see that 20 plus two X is equal to forty this side over here.

17
00:01:00,460 --> 00:01:03,100
Therefore X is equal to ten centimeter.

18
00:01:03,550 --> 00:01:05,620
All right, now, over here.

19
00:01:05,620 --> 00:01:06,760
Let this be it.

20
00:01:07,690 --> 00:01:12,610
OK, so over here, triangle e deep is the right angle triangle.

21
00:01:12,610 --> 00:01:12,890
Right.

22
00:01:13,090 --> 00:01:19,200
Therefore, 26 square is equal to eight squared plus X Square as per Pythagoras theorem.

23
00:01:19,540 --> 00:01:26,110
Now hence I can find it square as 26 square minus X square and X is equal to ten.

24
00:01:26,110 --> 00:01:27,190
We have found that over here.

25
00:01:27,610 --> 00:01:29,970
It's square is 26 square minus hundred.

26
00:01:30,190 --> 00:01:34,720
That's six, seven, six minus under and you'll get it as five seventy six.

27
00:01:34,930 --> 00:01:37,780
Now remember five seventy six is twenty four square.

28
00:01:38,140 --> 00:01:42,670
If you don't remember that you can just factor five seventy six so you will get it.

29
00:01:42,670 --> 00:01:46,450
As to the two in the twelve in the twelve to the square root of five.

30
00:01:46,450 --> 00:01:47,950
Seventy six is 212.

31
00:01:48,160 --> 00:01:49,700
That's twenty four over here.

32
00:01:50,140 --> 00:01:56,140
Now we have found the height and we know the two sides.

33
00:01:56,170 --> 00:02:00,190
Therefore area is equal to X by two in the twenty plus forty.

34
00:02:00,460 --> 00:02:04,660
That's twenty four by two into sixty and you will get the answer.

35
00:02:04,670 --> 00:02:06,640
Seven centimetres square.