How can I accurately measure the angle of my walls?

Question

I have a lot of walls that slant inward. To measure the angles at which they slant inwards, I used an app that looks like:

Was this the correct tool? Assuming it was, do I need to make sure I get the Y value to be as close to 0 as possible before taking the reading of the X value (which ultimately gives me the wall angle)?

Answer 1

You could maybe use the phone App tool but you would still have to translate the angle reading into lines on the pieces of wood. A far better tool was invented long long ago that direct measures the angle and then allows for direct transfer to the wood. It is called a carpenters bevel or a bevel square.