Hello I'm (Nice) and I'm very nice. 
Now I will show you how to create Triangles.
http://buildism.net/games/How-to--Build-a-triangle/8470
A game I created.
-Explanation-
First you create a block-brick-box or whatever you call it and start creating stairs on the both side. After you done the stairs on the both side's you will start creating 2 bricks on the both side on top of the stairs and rotate 'em with the Rotate tool into the format of a Triangle. Voila! Your done!
I hope this helped. You can also check the picture of my game. It shows you very clearly the format of the triangle and the bricks.
Thanks.
Now I will show you how to create Triangles.
http://buildism.net/games/How-to--Build-a-triangle/8470
A game I created.
-Explanation-
First you create a block-brick-box or whatever you call it and start creating stairs on the both side. After you done the stairs on the both side's you will start creating 2 bricks on the both side on top of the stairs and rotate 'em with the Rotate tool into the format of a Triangle. Voila! Your done!
I hope this helped. You can also check the picture of my game. It shows you very clearly the format of the triangle and the bricks.
Thanks.