How Do You Calculate Current I3 in This Complex Circuit?

[Mikesgto]

Homework Statement

In the circuit below find the current I3 (in A) when R1 = 12 Ω, R2 = 78 Ω, R3 = 30 Ω, R4= 69 Ω, R5 = 72 Ω, and V = 66 V.

[URL]https://s4.lite.msu.edu/res/msu/mmp/kap20/picts/hkirch2.gif[/URL]

Homework Equations

V=iR
1/Rtotal=(1/R1+1/R2...)

The Attempt at a Solution

I am thoroughly confused how to treat the resistors. What effect does the extra connection between R1 and R2 have on the diagram? It's making it hard to realize what's in series or what's in parallel.

 

[p21bass]

I don't see any diagram, so I don't know where to begin to help you.