- #1

Marioqwe

- 68

- 4

## Homework Statement

http://img11.imageshack.us/f/screenshot20110117at120.png/

The question is 2.3

## Homework Equations

Law of cosines and law of sines.

## The Attempt at a Solution

I used the law of cosines to find the resultant force. It is 139.1 lb. However, I get 113.1 degree for the direction of the resultant force. The textbook says that it is 67 degrees. I noticed that I get 67 degrees if I subtract 139.1 from 180 degrees. Why is this? Also, I am a little confused about significant figures. Why are they giving only two sig figs for the direction?

Thanks