According to the instructions, I have to make a 21.5 degree cut in a 2x4 piece of lumber.

Here’s a screenshot of the instructions: enter image description here

My question: can this measurement be done without having to buy a protractor or any other specialized tool?

Or even better, can I print out a protractor from the web?

  • Yes you can print a protractor from the Internet. Use a search engine to search the Internet for a printable Protractor.
    – Alaska Man
    May 21, 2020 at 1:03
  • Or use trigonometry and make some measurements. Your phone calculator will help if you turn it sideways ;-) Just be sure you are in degrees, not radians. Specifically, you want Tan (21.5°) which is 0.39391.
    – Ecnerwal
    May 21, 2020 at 1:10
  • My table saw has a angle guide , not real accurate but to tell the truth a table saw with a good guide is about the only way you will get close for a rip cut on a 2x4.
    – Ed Beal
    May 21, 2020 at 1:24

1 Answer 1


As pointed out in the comment, you can of course do it with a basic triangle calculator.

Do yourself a huge favor and buy a speed square. They are $10 and are useful for so many things beyond just marking an angle on a board.

  • Thanks. The problem is that the home depot here doesn’t have speed squares.
    – rbhat
    May 22, 2020 at 0:21
  • Thanks. I ended up buying one from Amazon. In the meantime I printed a protractor.
    – rbhat
    May 24, 2020 at 0:10

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