Warnings Active: Cube Dispenser, Cube Hitting Head

Make a portal on any surface (except through the energy field) and take the cube with you to land on the raised platform. Shoot through the hole in the wall to the other side, then take the cube with you into it and place it on the button. This teaches you about the line-of-sight principle for the portal gun, or more specifically the way it needs to be utilized in these puzzles.

Portal Walkthrough