That angle beyond the60angle is your120angle. This article has been viewed 94,397 times. Thanks for reading our article! If not, any tile or carpet laid will be noticeably 'off' from one side of the room to the other. At the end of this video you will learn use of set-squares. Gann Fans: A form of technical analysis based on the ideas that the market is geometric and cyclical in nature. You will need a scientific calculator to measure a perfect angle using only a framing square. Second, you need to decide the height (H) of the arc. The 3-4-5 method is also useful for smaller carpentry projects, ensuring that all your parts will fit together as planned. That line segment is an angle bisector, yielding two 30 angles. Label its endpoints. Locate two points on the line segment at either end. HOW TO: GIVEN AN ANGLE MEASURE IN DEGREES, DRAW THE ANGLE IN STANDARD POSITION. Rotate the protractor to align one leg of the angle with the baseline. "Building a patio in the middle of my lawn and want it to be square. The first step is to determine the width (W) of the arc that you want to draw. "I had to build a brick wall in a trench at right angles to an existing wall, and this system helped me obtain a. We use cookies to make wikiHow great.