Are these plants posionous?

Poison ivy or oak?

 

Why not Google "image" of P.O and P.I. and get a definitive answer.

 

Left and center photos show brambles (Rubus), right photo is one of the poisonous Rhus species. These never have the thorns or prickles of brambles, often do have glossy leaves.

 

Thanks for your responses. I had first tried the google method-but there were so many different images I couldn't really tell. I was just going wuth the "leaves of 3" philosophy.