in a horizontal tug of war ,Alex,Betty, and Charles pull horizontally on an automobile tire at the angles shown in the overhead view (see attaced file) the tire remains stationary in spite of the three pulls alex pulls with a force of magnitude 220 newtons and charles pulls with a force of magnitude of 170 newtons the direction of charles' force is not given . what is the magnitude of bettys force? what i need to know is when they find the components of Alex why do they use (180-47)=133 instead of the "natural choice of 47" ? why do they use the 133 degree algle alexes' force makes with the positive x-axis insted of 47 degree algle this force makes with the negative x-axis. choosing the wrong angle is totally messing me up big time. i can do the problem i just keep using the wrong angle. is there some general rule of what angle to use? my professor is terrible and my entire class is basically on it's own. i really need some understanding. thx in adcance.