1 00:00:00,720 --> 00:00:08,020 Let's do this question, ABCDE is a program in which it is perpendicular to KDDI, all right. 2 00:00:08,040 --> 00:00:12,360 So this angle over here is 90 degree AC is equal to five centimeter. 3 00:00:12,600 --> 00:00:14,780 B is equal to four centimeter. 4 00:00:15,060 --> 00:00:19,380 And the area of triangle area is six centimeter square. 5 00:00:20,070 --> 00:00:20,610 All right. 6 00:00:20,970 --> 00:00:25,830 Now find the perimeter and area of Ebiquity of the video. 7 00:00:25,830 --> 00:00:27,920 Give it a try and then let's do it together. 8 00:00:29,400 --> 00:00:30,270 All right, we're back. 9 00:00:30,300 --> 00:00:31,470 I hope you've given it a try. 10 00:00:31,710 --> 00:00:33,520 Let's do it together now. 11 00:00:34,080 --> 00:00:38,440 The area of E.T. is given a six centimeter square, right? 12 00:00:38,640 --> 00:00:44,730 And we know that area of a triangle is half in the base in the height because this is a 90 degree angle. 13 00:00:44,760 --> 00:00:48,720 If I take this as the base, the height is itself. 14 00:00:48,720 --> 00:00:48,990 Right. 15 00:00:49,230 --> 00:00:55,260 Therefore, the area of this triangle can be written as having to be into it, and that is given a six 16 00:00:55,260 --> 00:00:56,180 centimeter square. 17 00:00:56,550 --> 00:01:00,300 So it's given that B is equal to for that substitute that over here. 18 00:01:00,460 --> 00:01:06,850 So that gives half into four in the area is equal to six, therefore it is equal to three centimeter. 19 00:01:07,200 --> 00:01:08,910 What we have found this length over here. 20 00:01:09,390 --> 00:01:10,530 Let's market over here. 21 00:01:11,690 --> 00:01:18,130 OK, so now let's draw a triangle, ABC, this triangle over here, let's draw it over here. 22 00:01:18,770 --> 00:01:20,480 We have that side. 23 00:01:20,570 --> 00:01:22,070 It is three centimeter. 24 00:01:22,080 --> 00:01:23,930 Inside side is five centimeters. 25 00:01:23,930 --> 00:01:24,200 Right. 26 00:01:24,440 --> 00:01:29,300 Let's find X using Pythagoras Theorem Y because this angle over here is 90 degrees. 27 00:01:29,480 --> 00:01:35,180 And in the right angle triangle, we can say that hypotenuse square is equal to some of the squares 28 00:01:35,180 --> 00:01:36,410 of the other two sides. 29 00:01:36,830 --> 00:01:43,310 Twenty five is equal to nine plus X Square or you get X is equal to or centimeter. 30 00:01:43,820 --> 00:01:46,490 We have found that X is equal to four centimeter. 31 00:01:46,640 --> 00:01:47,910 Let's market over here. 32 00:01:48,170 --> 00:01:54,920 Now, in this triangle in the east, you know that it's the right angle. 33 00:01:54,920 --> 00:02:01,310 Triangle 80 square is equal to a square plus the square, but that's nine plus 16. 34 00:02:01,520 --> 00:02:04,880 Therefore you can see that it is equal to five. 35 00:02:05,330 --> 00:02:06,680 Root of twenty five is five. 36 00:02:07,090 --> 00:02:09,480 OK, so let's proceed. 37 00:02:09,500 --> 00:02:11,330 So we have identified these lengths. 38 00:02:11,570 --> 00:02:15,470 Now we need to find the perimeter and area of ABCDE. 39 00:02:15,650 --> 00:02:16,830 What would be the perimeter. 40 00:02:17,090 --> 00:02:23,860 That's two times length plus breadth or two times side by side because these two sides are equal and 41 00:02:23,900 --> 00:02:25,000 these two sides are equal. 42 00:02:25,010 --> 00:02:31,700 So perimeter is equal to two times 80 plus D.C. and that gives you two times five plus eight, which 43 00:02:31,700 --> 00:02:33,070 is equal to twenty six. 44 00:02:33,440 --> 00:02:38,930 And what is the area of A, B, C, D we just need to base into height. 45 00:02:39,080 --> 00:02:44,100 So if I take DC as the base that's easy into 80. 46 00:02:44,630 --> 00:02:45,530 What is DC. 47 00:02:45,540 --> 00:02:46,840 This is four plus four. 48 00:02:47,000 --> 00:02:49,180 That gives you eat what is easy. 49 00:02:49,190 --> 00:02:49,820 That's three. 50 00:02:50,030 --> 00:02:54,800 So the areas is the three which is equal to twenty four centimeter square.