Start from the origin and go east for 80km. Then go north 192 km. Make a drawing.
1. Draw a hor. line from the origin on
the positive x-axis(due East). Label it
80km.
2. Draw a ver. line upward from the end of the hor line parallel to the positive y-axis(due North) and label it 192km.
If you drove along the given parh, you
would have traveled 272km(80km+192km).
If you took a st. line from the origin
to the final destination, you would have traveled:
d = sqrt((80)^2+(192)) = 208km.
tanA = Y/x = 192 / 80 = 2.4,
A = 67.38 deg.
R = X / cosA = 80 / cos67.38 = 208km..