DEGREE MEASURE OF AN ANGLE

The degree is a unit of measurement of angles and is represented by the symbol °.

In degrees, we split up one complete rotation into 360 equal parts and each part is one degree, denoted by 1°. Thus, 1° is 1/360 of one complete rotation.

To measure a fraction of an angle and also for accuracy of measurement of angles, minutes and seconds are introduced. One minute (1') corresponds to 1/60 of a degree and in turn a second (1'') corresponds to 1/60 of a minute (or) 1/3600 of a degree.

Classification of Pair of Angles

We shall classify a pair of angles in the following way for better understanding and usages.

(i) Two angles that have the exact same measure are called congruent angles.

(ii) Two angles that have their measures adding to 90° are called complementary angles.

(iii) Two angles that have their measures adding to 180° are called supplementary angles.

(iv) Two angles between 0° and 360° are conjugate if their sum equals 360°.

Degrees, Minutes and Seconds

(i) The concept of degrees, minutes and seconds, is analogous to the system of time measurement where we think of a degree representing one hour.

(ii) Observe that

59.0854° = 59° + 0.0854°

0.0854° = 0.0854° ⋅ (60'/1°) = 5.124'

5.124' = 5' + 0.124'

0.124' = 0.124' ⋅ (60"/1') = 7.44"

Thus, 

59.0854° = 59°5'7.44"

(iii) Also notice that

34°51'35" = 34.8597°

and

90° - 36°18'47" = 53°41'13"

Related Pages

Angles in standard position

Coterminal angles

Apart from the stuff given above, if you need any other stuff in math, please use our google custom search here.

Kindly mail your feedback to v4formath@gmail.com

We always appreciate your feedback.