Last June my power went out on half of my house when I let the landlord know he then told the owner so the owner came to my house and looked and checked wires he said he could not fix it because it was the wiring so he rigged it to work he ran a wire from a working plug to the outlet that stopped working it has been almost a year . Is this dangerous for my family

Without really seeing it, yes, it sounds very very dangerous. He has a obligation to fix it accourding to code

One plug, or 'half the house?' Can you describe this better? What are you running off this one extension cord?

Last June my power went out on half of my house when I let the landlord know he then told the owner so the owner came to my house and looked and checked wires he said he could not fix it because it was the wiring so he rigged it to work he ran a wire from a working plug to the outlet that stopped working it has been almost a year . Is this dangerous for my familyOK, first, please type in sentences so people can more easily understand what you are saying.
There is no way to tell if something is dangerous or not from your description. All you can do is call the landlord and demand they have a real electrician fix, or at least check, the issue.
I am not sure of the legality of this, but if they are not responsive you can have an electrician fix it and deduct the money from your rent. Towns and cities are usually very responsive to safety complaints from tenants so they may be on your side with this. I'd call your local building office to check.

Is this a doublewide? If so, have them check the crossover connection. If a regular home, have the power company check the main power feed as you may have lost 1/2.

Since the information is sketchy, I'll just guess. You lost a phase. Do you have any 220 appliances? If he just jumpered form one outlet to another that quit working, and that phase happens to come back... you will have a dead short. It will blow fuses or trip breakers. Can you give more details? At any rate, since you do not know how to proceed, you need to find a professional to fix this... and send the bill to the landlord. It could be a dangerous situation, and can't be fixed or determined by an online forum.