# Degree Measurement

A degree is a unit used to measure angles.

One degree is equivalent to one 360th of a full circle. $$ 1° = \frac{1}{360} $$

The system that uses degrees is known as the sexagesimal system.

**Note**: The division of a circle into 360 parts is linked to the duration of the year. In ancient times, it was believed that the solar year lasted 360 days, so the cycle of seasons was represented by a circle.

The subdivisions of a degree are:

**Minutes**

A degree is divided into 60 parts, called minutes, usually denoted by a single prime. $$ 1°=60' $$**Seconds**

Each minute is further divided into 60 parts, called seconds, usually denoted by a double prime. $$ 1'=60" $$

**Note**: The subdivisions of a degree were introduced in the 2nd century AD by Ptolemy, known as first minutes and second minutes. The choice of 60 parts is probably because the number 60 has many divisors.

**A practical example**

An angle of 45 degrees, 10 minutes, and 22 seconds is written as:

$$ 45° \ 10' \ 22" $$

And so on.