1 00:00:00,490 --> 00:00:01,640 Let's do this question. 2 00:00:01,810 --> 00:00:05,850 This is a very important question, and these type of questions are very frequent. 3 00:00:06,070 --> 00:00:09,070 Let's do this or here you have a circle, right? 4 00:00:09,340 --> 00:00:13,650 a.D.A and BCR tangent to the circle and angle. 5 00:00:13,660 --> 00:00:17,290 ABC is equal to Angle HCB. 6 00:00:17,860 --> 00:00:19,880 That's equal to seventy five degrees. 7 00:00:20,140 --> 00:00:23,320 Now we need to find angle C or B, all right. 8 00:00:23,500 --> 00:00:26,930 Because the video give it a try and then let's do it together. 9 00:00:27,460 --> 00:00:27,910 All right. 10 00:00:27,910 --> 00:00:28,880 Let's do it together. 11 00:00:29,260 --> 00:00:33,730 We know that these two angles are equal right angle HCB. 12 00:00:35,010 --> 00:00:39,330 Is equal angle, ABC is equal to seventy five degrees with these two angles. 13 00:00:39,400 --> 00:00:42,980 Seventy five degrees therefore I can find angle eight. 14 00:00:43,260 --> 00:00:46,200 That would be 180 minus seventy five plus seventy five. 15 00:00:46,530 --> 00:00:46,890 Right. 16 00:00:46,990 --> 00:00:50,550 So 180, minus 150 gives you thirty degrees to angle. 17 00:00:50,550 --> 00:00:52,440 It is equal to thirty degrees. 18 00:00:52,950 --> 00:00:54,270 All right, let's proceed. 19 00:00:54,420 --> 00:00:57,540 Let's join all with A, B, F and E. 20 00:00:59,280 --> 00:01:06,090 All right, now we know that these three lines are tangent to the circle, right to these angles have 21 00:01:06,090 --> 00:01:07,230 to be 90 degrees. 22 00:01:07,480 --> 00:01:07,900 All right. 23 00:01:08,100 --> 00:01:12,200 Now you will see that the FBI, that's B or FBI. 24 00:01:12,450 --> 00:01:13,580 This is a kind. 25 00:01:15,330 --> 00:01:23,640 Why is that so, or is it because both of them are radiuses of the circle and Beedi is equal to BSF 26 00:01:23,790 --> 00:01:29,490 because beauty and BFX are tangents from an exterior point to a circle. 27 00:01:29,730 --> 00:01:33,120 Now, you will learn more about this in this section on Sakalys. 28 00:01:33,900 --> 00:01:40,170 Whenever you draw tangents to a circle from an exterior point, they will be of equal length. 29 00:01:40,290 --> 00:01:45,630 That is beedi is equal to be if the beauty is equal to the left and Audy is equal to. 30 00:01:45,630 --> 00:01:51,470 Or if you have two pairs of adjacent sites that are equal and the FBI is a kind. 31 00:01:51,930 --> 00:01:53,250 All right, let's proceed. 32 00:01:53,450 --> 00:02:01,200 Now we know that the longer diagonal is an angle bisecting, so angle one is equal to angle. 33 00:02:02,010 --> 00:02:09,990 Similarly, you will see in F all e c this is also a because of is equal weight and F.C. is equal to 34 00:02:09,990 --> 00:02:10,410 see. 35 00:02:10,560 --> 00:02:15,660 Why is F.C. equal to C because they are engines from an exterior point to a circle. 36 00:02:15,840 --> 00:02:20,010 And whenever you have tendons from an extra point to a circle they'll be equal. 37 00:02:20,160 --> 00:02:21,940 That is Sieff is equal to see. 38 00:02:22,200 --> 00:02:24,240 So you have two sets of equal sides. 39 00:02:24,420 --> 00:02:33,300 And if E C is a kite and in a kite, the longer angled bisects the the the longer diagonal bisects the 40 00:02:33,300 --> 00:02:33,660 angle. 41 00:02:33,840 --> 00:02:35,940 Therefore angled three is equal to angle four. 42 00:02:36,210 --> 00:02:36,600 Right. 43 00:02:36,840 --> 00:02:37,230 All right. 44 00:02:37,230 --> 00:02:44,310 Let me know that down over here now, angrily and angrily, both are 90 degree angles. 45 00:02:44,310 --> 00:02:44,650 Right? 46 00:02:44,880 --> 00:02:45,690 Why is that so? 47 00:02:45,720 --> 00:02:50,420 Because it's mentioned that 80 and 80 are tangents to this circle. 48 00:02:50,670 --> 00:02:56,470 Now, when you have a tangent and the tangent intersects a circle at one point, if you join that point 49 00:02:56,470 --> 00:03:00,750 to the center of the circle, the angles will form will be 90 degrees. 50 00:03:00,930 --> 00:03:03,990 Now, you will learn more about this in this section on circles. 51 00:03:04,200 --> 00:03:04,680 All right. 52 00:03:04,830 --> 00:03:09,020 Now, Angley and Angley are both ninety degree angles, right? 53 00:03:09,180 --> 00:03:11,640 Therefore, you can find that angle the. 54 00:03:11,730 --> 00:03:13,040 All right. 55 00:03:14,150 --> 00:03:22,430 Make some space over here and will be or eat this angle over here will be 360 minus 90, plus 90, plus 56 00:03:22,430 --> 00:03:22,880 30. 57 00:03:24,270 --> 00:03:25,150 Why is that so? 58 00:03:25,380 --> 00:03:32,190 Because A, B or C is a quadrilateral, right, and we know that the sum of the angles of a quadrilateral 59 00:03:32,340 --> 00:03:33,890 is equal to 360 degree. 60 00:03:34,080 --> 00:03:38,010 And we know that this angle is 90, this angle is 90, and this angle is 30. 61 00:03:38,130 --> 00:03:38,400 Right. 62 00:03:38,850 --> 00:03:44,790 So the only has to be 360, minus 90, plus 90, plus 30. 63 00:03:45,000 --> 00:03:52,920 And just as a side note, even 80 or E is also a kite because all is equal to oil and it will be equal 64 00:03:52,920 --> 00:03:53,490 to eight. 65 00:03:53,700 --> 00:03:54,090 All right. 66 00:03:54,090 --> 00:04:00,780 Let's proceed to let's find Angle or that would be one 50 degrees from this equation on solving. 67 00:04:01,020 --> 00:04:03,900 We get angle is equal to 150 degrees. 68 00:04:04,230 --> 00:04:10,050 Now, that is equal to from the figure two times angle two plus two times angle three. 69 00:04:10,050 --> 00:04:10,280 Right. 70 00:04:10,320 --> 00:04:13,950 Because angle one and two are equal and three and four are equal. 71 00:04:13,980 --> 00:04:20,310 So this is two times angle two plus two times angle three, therefore angle C or B, which is what we 72 00:04:20,310 --> 00:04:27,900 need to find, which is equal to angle two plus angle three will be equal to half of one fifty. 73 00:04:27,900 --> 00:04:28,250 Right. 74 00:04:28,380 --> 00:04:31,790 That's one fifty by two which is equal to seventy five degrees. 75 00:04:31,950 --> 00:04:33,750 And that is your answer.