How do you build a half pipe?

me and m dad are going to build a half pipe in our back yard but we dont no how dose anyone no a website we can get the plans are something we can print out that shows us how to build a half pipe I realy need help if anyone noes a website please tell me

Hope this is what you mean:

http://en.wikipedia.org/wiki/Half_pipe

Good luck !!

if you google it you'll get back a million ways to do it. good luck.