Given three points, it is always possible to draw a circle that passes through all three. This page shows how to construct (draw) a circle through 3 given points with compass and straightedge or ruler. It works by joining two pairs of points to create
10∠AJP = ∠AKQCorresponding angles. AB is a transversal across the parallels PE, QF 11Triangles AQK, APJ are similarAAA. ∠PAJ is common to both, and (9), (10). SeeSimilar triangles test, angle-angle-angle. 12Triangles AQK is twice the size of APJAP = PQ. Both drawn with same ...
You don’t need to go any further unless you’re really curious. If you are, plot Deviation (horizontal axis) against Magnetic (vertical axis). You should get something like a sine-curve. Not perfect, but passable (the zero deviation points will probably not be at 000 and 180 degrees)....
To make a right angle, use a protractor to measure and draw a right angle on a piece of paper. Then, use a ruler or a tape measure to measure the length of the right angle. Finally, use a pencil to draw a line connecting the two points. ...