How large shold a fenced area be for two Goldens

Question
Hello,  Thank you in advance for your advice. I have two six month old Goldens (male & female) and plan on having a 5 ft enclosed chain link fenced area installed so they are safe when outside. I know that I need a good dog house (it's going to be a cedar duplex !) shade, etc.. My question is: is 75ft wide X 150 ft long to big ? about the first 100ft is lawn, the remaining 50ft is wooded (i live in the northeast US). The dogs currently like to 'take care of their private business' in the woods so I thought i'd have the house, water, food, toys on the grass end and hopefully the wooded end can be the potty ? Does this makes sense ?  5 Ft high enough ? Not sure what my plan is to discourage them from digging under... hopefully they will not watch the movie 'the great escape' and get any ideas....  8-)

Answer
Sounds reasonably good to me.  If they decide to, I am afraid they can still jump a 5' fence.  I think fence jumping can be a learned experience.  A 5 foot fence may be high enough that the dogs never think of jumping it.  I put up a 5' fence 5 years ago, and so far none of my Labs or one Shepherd jumped it.  I put down limestone flagstone under it before I put the fence up.  A ton of work, but by hauling the stone myself, cheap.   

None of my dogs have been ones determined to escape.  The one Lab jumped a 4' gate at a friend's place when she became separated from us, but never seemed to want to get out of the fence at home.