PI() radians = 180 degree
2 PI() radians = 360 degree
                    PI()/2 radians = 90 degree
Example
X (degree)                     90 It must be ≤ 90 or ≤ -90
X (radians)          1.5707963268
X (degree)                     90
Pi ∏                 3.1415926536
Pi /2                1.5707963268
Sin                             1 Sin of an Angle (Angle must be in radians)
Arc Sin (radians)    1.5707963268 Arc Sin of a number in radians in the range -Pi/2 to Pi/2
Angle (degree)                 90
tan                 1.6324552E+16
arc tan (radians)    1.5707963268
Angle( degree)                 90
         180   3.141593
3.1415926536
         180
3.1415926536
1.5707963268
           1         1
1.5707963268   #VALUE!
          90   #VALUE!
          Excel:
          =ACOS( SIN(lat1)*SIN(lat2) + COS(lat1)*COS(lat2)*COS(lon2-lon1) ) * 6371000 (m)
          (or with lat/lon in degrees):
          =ACOS( SIN(lat1*PI()/180)*SIN(lat2*PI()/180) + COS(lat1*PI()/180)*COS(lat2*PI()/180)*COS(lon2*PI()/180
         CI60XC351                          CI13XC912                                      P1
degree   39.81359722                         39.80336                                            39
          -84.1336556                        -84.1061                                           -84
radian   0.694878359                           0.6947
           -1.4684093                        -1.46793
         2.610 Km                                                                          2.610 Km
                   2616.3 mts               from radian formula                             6371000
                   2616.3 mts               fron degree formula                1 deg Lat = 111194.9 mts
         0.010233333 1137.894749292
         -0.02758056 -2383.353127324
                      2641.055961163
         Bearing         β = atan2(Y,X)
         X               X = cos θb * sin ∆L
         Y               Y = cos θa * sin θb – sin θa * cos θb * cos ∆L
         Kansas City: 39.099912, -94.581213                           39.099912 -94.5812
         St Louis: 38.627089, -90.200203                              38.627089 -90.2002
                                                                                 4.38101
         X                    0.059676687
         Y                  -0.0068126195
         Bearing             1.6844630626
         B in degree      96.51262423
m)
/180)*COS(lon2*PI()/180-lon1*PI()/180) ) * 6371000 (m)
          P2                                P1               P2
                 40                                39              39
                -84                               -84             -85
                                            2.610 Km
                                               1633349
                                  1 deg Lat = 86414.25 mts
           0.682422 -1.65075358
            0.67417 -1.57429053
                    0.076463049
Calculating Bearing or Heading angle between two points:
So if you are from GIS field or dealing with GIS application, you should know bearing and how to calculat
tool for bearing:
Let ‘R’ be the radius of Earth,
‘L’ be the longitude,
‘θ’ be latitude,
‘β‘ be Bearing.
Denote point A and B as two different points, where ‘La’ is point A longitude and ‘θa’ is point A latitude,
measured from North direction i.e 0° bearing means North, 90° bearing is East, 180° bearing is measured
Note: If bearing is denoted with +ve or –ve initials whose values lies between 0° to 180°, then –ve is deno
Formula to find Bearing, when two different points latitude, longitude is given:
Bearing from point A to B, can be calculated as,
β = atan2(X,Y),
where, X and Y are two quantities and can be calculated as:
X = cos θb * sin ∆L
Y = cos θa * sin θb – sin θa * cos θb * cos ∆L
Lets us take an example to calculate bearing between the two different points with the formula:
Kansas City: 39.099912, -94.581213
St Louis: 38.627089, -90.200203
So X and Y can be calculated as,
X = cos(38.627089) * sin(4.38101)
X = 0.05967668696
And
Y = cos(39.099912) * sin(38.627089) – sin(39.099912) * cos(38.627089) * cos(4.38101)
Y = 0.77604737571 * 0.62424902378 – 0.6306746155 * 0.78122541965 * 0.99707812506
 Y = -0.00681261948
So as, β = atan2(X,Y) = atan2(0.05967668696, -0.00681261948)
       β = 96.51°
This means, from Kansas City if we move in 96.51° bearing direction, we will reach St Louis.
w bearing and how to calculate bearing with formula. Let us look on formula and
 e and ‘θa’ is point A latitude, similarly assume for point B. Bearing would be
ast, 180° bearing is measured to be South, and 270° to be West.
en 0° to 180°, then –ve is denoted for South and West sides.
iven:
nts with the formula:
os(4.38101)
 .99707812506
l reach St Louis.
Point A     Point B     Lat A (deg)  Long A (deg) Lat B (deg)  Long B (deg) La A (rad)
CI60XC351   CI13XC912    39.81359722 -84.13365556 39.80336389 -84.106075 0.694878359
CI13XC912   CI60XC351    39.80336389    -84.106075 39.81359722 -84.13365556 0.694699753
CI13XC912   CI03XC352    39.80336389    -84.106075 39.77738056 -84.14188333 0.694699753
CI13XC912   CI14XC285    39.80336389    -84.106075 39.82595278 -84.06907222 0.694699753
Long B (rad) Lat B (rad) Long B (rad) ∆L (deg) ∆L (rad) X       Y        Bearing (rad)
 -1.468409301 0.694699753 -1.46792793 0.027581 0.000481 0.00037 -0.00018 2.0205966992
  -1.46792793 0.694878359 -1.4684093 -0.02758 -0.00048 -0.00037 0.000179 -1.120687769
  -1.46792793 0.694246259 -1.4685529 -0.03581 -0.00062 -0.00048 -0.00045 -2.327375688
  -1.46792793 0.695094004 -1.46728211 0.037003 0.000646 0.000496 0.000394 0.899056858
Bearing(deg) Bearing Abs (deg) OK
         115.8                 115.8
         -64.2                 295.8
        -133.3                 226.7
          51.5                  51.5
Point A     Point B     Lat A (deg)  Long A (deg) Lat B (deg)  Long B (deg) La A (rad)
CI60XC351   CI13XC912    39.81359722 -84.13365556 39.80336389 -84.106075 0.694878359
CI13XC912   CI60XC351    39.80336389    -84.106075 39.81359722 -84.13365556 0.694699753
CI13XC912   CI03XC352    39.80336389    -84.106075 39.77738056 -84.14188333 0.694699753
CI13XC912   CI14XC285    39.80336389    -84.106075 39.82595278 -84.06907222 0.694699753
Long B (rad) Lat B (rad) Long B (rad) ∆L (deg) ∆L (rad) X       Y        Bearing (rad)
 -1.468409301 0.694699753 -1.46792793 0.027581 0.000481 0.00037 -0.00018 2.0205966992
  -1.46792793 0.694878359 -1.4684093 -0.02758 -0.00048 -0.00037 0.000179 -1.120687769
  -1.46792793 0.694246259 -1.4685529 -0.03581 -0.00062 -0.00048 -0.00045 -2.327375688
  -1.46792793 0.695094004 -1.46728211 0.037003 0.000646 0.000496 0.000394 0.899056858
Bearing(deg) Bearing Abs (deg) OK      Sec Point A Point A Azim    Sec Point B Point B Azimut
         115.8                 115.8
         -64.2                 295.8
        -133.3                 226.7                         270                            35
          51.5                  51.5             3           270             1              35
M=(A - 90)N=(A + 90)P(B - 30) Q(B + 30) Front or Back? P-B relat to Az A    P-B relat to Az A
      180       360         5        65 Back                        218.5                141.5
Az B relat to Az A    Az B relat to Az A
              235.0                 125.0
Angle   Condition 1