NICET - Highway Construction Inspection Practice Exam

How do you convert from DMS (Degrees Minutes Seconds) to Decimal?

1. D = degrees + (minutes/60) + (seconds/3600)

2. D = degrees - (minutes x 60) - (seconds x 3600)

3. D = seconds + (minutes/60) + (degrees/3600)

4. D = degrees + (seconds/3600) - (minutes/60)

The correct answer is: D = degrees + (minutes/60) + (seconds/3600)

The conversion from Degrees Minutes Seconds (DMS) to Decimal Degrees is done using a specific formula that accurately reflects how each component contributes to the overall value. The correct method involves taking the degree measurement as the whole number and then adding fractions derived from the minutes and seconds. In the formula D = degrees + (minutes/60) + (seconds/3600), the degrees remain intact while the minutes and seconds are converted into decimal form. Since there are 60 minutes in a degree, dividing minutes by 60 transforms them into the corresponding decimal fraction of a degree. Similarly, since each minute is divided into 60 seconds, seconds are divided by 3600 (60 seconds for each of the 60 minutes in a degree) to convert them into degrees. This formula allows for a straightforward transition from the traditional DMS format into a single decimal representation, which is often easier to use in calculations and geographic information system (GIS) applications. Thus, this method is the standard approach utilized in geographical and navigational calculations.