which country has the most pacific ocean coastline?

Either Australia or Chile

The answer is most likely Indonesia. Islands generally have extremely large coastlines and since the nation is made up of so many different islands, it most likely has the most. This stems from the fractal work of Benoit Mandelbrot

Chile.

Australia's East coast is divided by the Pacific Ocean and the Tasman Sea.

I regret to differ from the learned teacher of maths but Indonesia has very little contact with the Pacific Ocean.

I agree with the professor about islands having long coastlines. Indonesia, however, is only partially in touch with the Pacific, and the rest is with the Indian Ocean. Same for Australia.

The correct answer would have to be either Japan or Philippines, both island nations in the Pacific.

one connection for this is http://geography.about.com/library/cia/blcpacific.htm

I will let that be a start for you.
Japanese coastline: 29751 km. http://geography.about.com/library/cia/blcjapan.htm

philippines coastline 36289 km
http://geography.about.com/library/cia/blcphilippines.htm

here is yet another link, with coastline lengths for all countries: http://en.wikipedia.org/wiki/List_of_countries_by_length_of_coastline