iphoto, imovie, iweb missing after mountain lion upgrade...

I have a mid 2010 iMac that I have kept up to date and recently upgraded to Mountian Lion. Everything has been fine except that I noticed that iLife was missing right after the update... And I didn't purchase it in the app store because it came with my iMac. In fact, the iMac came with Snow Leopard on it I think. But I haven't the slightest idea where that disk is because we lost a few things that I haven't located yet in our move last year. I have another copy of Snow Leopard that I goes to my 2009 MacBook that I already had. It seems quite frustrating that the programs just disappeared and they've never done that before on any other upgrade! I have no need to purchase and upgrade to iLife 11 as I only use iPhoto and iMovie for iPhone photos/video because I have everything else in LightRoom already. But I would like iPhoto/iMovie back! How do I go about doing this? Can i use my backup to get it back somehow? Just confused on how to tget it back and my searches yielded very little... Thanks!