Checking For Square Video
What is square? Are they talking about a framing square? No, they are indicating the all the corners in a project are 90 degrees. There is a way to check your object for square without doing a lot of fancy math.
To check a wall for example, make sure that the top plate and the bottom plate of any of the walls are the same length. In addition, check that all the wall studs are the same length. If so, you will have a rectangular with you assembly the components.
Now, using a tape measure, measure the length from one corner to the opposite diagonal corner. Then measure the opposite set of corners. Adjust your wall or deck frame until these measurements are the same distance. Then you will have a nice square wall or frame.
Why is this important? When you go to install plywood or drywall or deck flooring, it will be so much easier if things are square.