“It is an area of around 367,000 square miles (950,000 km2) that overlaps the mountains of three countries of Southeast Asia: Myanmar, Laos and Thailand.” (1)
“The Golden Triangle designates the confluence of the Ruak River and the Mekong River, since the term has been appropriated by the Thai tourist industry to describe the nearby border tripoint of Thailand, Laos and Myanmar.” (2)
[1]-http://en.advisor.travel/poi/Golden-Triangle-%28Southeast-Asia%29-19862
[2]-http://en.wikipedia.org/wiki/Golden_Triangle_%28Southeast_Asia%29