With angle measurement, so far we have used only degrees for measuring angles. However sometimes, we will need to use smaller angle measurement mainly for accuracy purposes.
Degrees are divided into minutes and seconds, just like in time measurement.
1 degree = 60 minutes (represented as 60′)
1 minute = 60 seconds (represented as 60″)
For example, 15 degrees, 28 minutes and 43 seconds is written as 15° 28′ 43″.
Tip for using scientific calculator
To enter 15° 28′ 43″, press 15, the key DMS, 28, the key DMS again, 43, and finally DMS.
Also remember, degrees are divided in 60s. Half a degree is 30 minutes.
So 15.5° = 15° 30′.
Rounding off angles
To round off angles, the half way point of one degree is 30 minutes, and that of a minute is 30 seconds. So if the number of minutes is 30 or more, you can round it up to the next degree. Similarly if the seconds are 30 or more, you can round it up to the next minute.
For example, 27° 46′ 25″ can be rounded off to
- nearest degree is 28° (since 46′ > 30′, therefore round up).
- nearest minute is 27° 46′ (since 25″ < 30″, therefore round down).
Here’s how to calculate angle sizes