1
00:00:00,660 --> 00:00:09,510
Let's do this question in Rectangle ABCDE, find angle DCE, that's this angle angle HCB.

2
00:00:10,440 --> 00:00:11,430
That's this angle.

3
00:00:12,410 --> 00:00:19,190
And angle or that's this angle over here now pause the video, give it a try, and then let's do it

4
00:00:19,190 --> 00:00:19,650
together.

5
00:00:20,090 --> 00:00:20,970
All right, we're back.

6
00:00:20,990 --> 00:00:23,270
I hope you've given it a try over here.

7
00:00:23,270 --> 00:00:31,970
You will see that angle, B or C is equal to angle or the right or B and B or C or vertically opposite

8
00:00:31,970 --> 00:00:32,420
angles.

9
00:00:32,720 --> 00:00:37,410
Therefore, because this angle is 60 degree, this angle also will be 60 degrees.

10
00:00:37,730 --> 00:00:38,140
All right.

11
00:00:38,300 --> 00:00:41,660
Now, let me mark these two angles as angle one and angle two.

12
00:00:41,900 --> 00:00:44,330
They are also vertically opposite angles.

13
00:00:44,330 --> 00:00:44,590
Right.

14
00:00:44,780 --> 00:00:46,340
But they also will be equal.

15
00:00:46,670 --> 00:00:54,380
Therefore, angle one, angle two plus 60 plus 60 is equal to 360 degree because it's making one complete

16
00:00:54,380 --> 00:00:55,040
revolution.

17
00:00:55,190 --> 00:00:55,540
Right.

18
00:00:55,670 --> 00:01:01,090
Therefore, you can find that angle one equals the angle two is equal to 120 degrees.

19
00:01:01,520 --> 00:01:04,220
So that's also equal to angle.

20
00:01:04,220 --> 00:01:06,800
It will be will we have this part done?

21
00:01:06,920 --> 00:01:14,660
Angle is equal to 120 degrees now because this is a rectangle we know that already is equal to Orsi.

22
00:01:14,840 --> 00:01:18,200
Right, because diagonals are equal and bisect each other.

23
00:01:18,530 --> 00:01:23,540
Now let me mark these angles as angle three, angle four over here.

24
00:01:23,750 --> 00:01:28,670
Now angle three is equal to angle four because Audy is equal to Orsi.

25
00:01:28,670 --> 00:01:31,160
So it's forming an isosceles triangle over here.

26
00:01:31,400 --> 00:01:34,780
Right triangle or this is isosceles.

27
00:01:35,060 --> 00:01:39,100
Now we know that angle two is equal to 120 degrees.

28
00:01:39,110 --> 00:01:45,020
So this is 120 degrees, both because angle three is equal to and therefore we can find that this is

29
00:01:45,020 --> 00:01:45,920
equal to.

30
00:01:48,030 --> 00:01:49,410
One eighty minus.

31
00:01:50,360 --> 00:01:54,930
Anger too, divided by two, right, that gives you 30 degree, right?

32
00:01:55,070 --> 00:01:57,290
That's one minus 120.

33
00:01:57,290 --> 00:02:00,800
That sixty 60 by two gives you a 30 degree angle.

34
00:02:00,810 --> 00:02:03,860
Four is equal to 30 degree angle.

35
00:02:03,870 --> 00:02:06,050
DCA is equal to 30 degrees.

36
00:02:06,460 --> 00:02:06,890
All right.

37
00:02:07,070 --> 00:02:08,470
Now let's proceed.

38
00:02:08,750 --> 00:02:11,890
What would be angle is c.B.

39
00:02:12,320 --> 00:02:14,540
That's the next one that we need to find.

40
00:02:14,540 --> 00:02:15,380
Right angle.

41
00:02:15,380 --> 00:02:17,960
ACB will be 90 minus angle four.

42
00:02:18,290 --> 00:02:18,670
Right.

43
00:02:18,770 --> 00:02:20,480
So that's 90 minus 30.

44
00:02:20,480 --> 00:02:23,210
And you get the answers, 60 degrees.