You walk 27 m to the north, then turn 59° to your right and walk another 42m. How far are you from where you originally started?
Suppose you draw a diagram, and label things as follows:
P = starting point
Q = turning point
R = final location
Angle PQR = 180-59 = 121°
So, using the law of cosines,
PR^2 = 27^2 + 42^2 - 2*27*42*cos121°
Now just crank it out.