Trigonometry
This question is related to sexagesimal system question 3 Ex 6.1
Transcript
00:00This is question number 3 of exercise 6.1.
00:04Convert the following measure of angle in degrees and write the answer correct to 4 decimal places.
00:10You have to convert these quantities in degrees.
00:14You have 135 minutes. You have to convert them in degrees.
00:19We have 60 minutes in 1 degree.
00:22Simply, when we have to see in 135 minutes that how many degrees will be there, we will divide it.
00:29You will divide 135 by 60.
00:35You can easily do this with a calculator.
00:38So, you are getting 2.25 degrees. That's it.
00:43In the second part, you have 150 seconds.
00:48You have to convert this also in degrees.
00:51In 1 degree, you have 60 minutes. In 1 minute, you have 60 seconds.
00:55In 1 degree, you have 3600 seconds.
00:58So, basically, we have to go from seconds in degrees.
01:02So, we will divide 3600 seconds by 150.
01:1215 divided by 360 will be 0.04166.
01:19Calculator will give you the answer like this.
01:21But, you have to convert it to correct to 4 decimal places.
01:26So, we will round off this.
01:280.041.
01:30Now, I have to ignore this 6.
01:33Whether it is 5 or a bigger number than 5, we ignore it.
01:36So, the rule of rounding off is that we make it 1 plus.
01:40That's why you will write 7 here.
01:43So, you have equal 150 seconds.
01:470.0417 degrees.
01:54In the third part, we have 60 degrees and 60 minutes.
01:59We will not touch degrees because we have to convert it in degrees.
02:03It will be like this.
02:05Your 60 minutes, you divide it by 60.
02:11It will be converted into degrees.
02:1460 degrees plus 1 degree will be equal to 61 degrees.
02:21In the fourth part, you have 45 degrees, 45 minutes and 45 seconds.
02:29We have to convert all these into degrees.
02:3345 degrees will be like this.
02:37Now, the 45 minutes you have, we will divide it by 60.
02:43It will be converted into degrees.
02:45Similarly, we will divide 45 seconds by 3600.
02:51It will be converted into degrees.
02:53Because 1 degree has 3600 seconds.
02:57When we solve this, it will be 45 degrees.
03:02This is going to be 0.75.
03:06Here, we have 0.125 degrees.
03:11By adding these three numbers, what we get is 45.7625 degrees.