# [Trusses] Problem finding forces in members

1. Nov 24, 2014

### student314

Can anyone please explain where does 5/sqrt29 and 3/sqrt34 come from? I already got BC/know how to find BC, but in my own method, I tried to use moment about A or B, knowing that there is HGx, HGy & HCy, HCx -- there are way too many unknowns @ H.

So, looking at this, I'm wondering where does 5/sqrt29 and 3/sqrt34 come from? Please see the image for reference:

http://i.imgur.com/4ruELnE.png

Thank you

2. Nov 24, 2014

### student314

Apparently I'm told to use the system of equations to find HG? Or HC? What does this mean, and how?

3. Nov 24, 2014

### SteamKing

Staff Emeritus
When you see factors like 5/Sqrt(29) or 3/Sqrt(34) in truss problems, these almost invariably arise from the geometry (or more accurately, the trigonometry) of a truss member.

In the equation for ΣMC , what is the length of member HG? What is the horizontal component of the force in member HG?

4. Nov 24, 2014

### student314

HGx = HG(5/sqrt(29))? Then times 5 distance to moment C?

God, I'm so tired, I've been working and trying hard to figure out all day, I'm going to sleep for now

5. Nov 24, 2014

### SteamKing

Staff Emeritus
Yep.