Learn how to do a rotation in geometry with this video! First step is to pout the pencil into the compass. Adjusting the pencil and compass needle is same. Suppose you want 165 degree size circle. Measure the reading with compass in protractor. Note the point and adjust the compass. After place the sharp end of the compass at the point and rotate the compass the circle will enabled. Next use protractor. We see 75 degree acute angle. Place the protractor on the line and mark the reading we want, which is now 75 degrees. So mark the point where the 75 degree is enabled put that mark on the protractor. After we draw the line, you have 75 degree acute angle. Geometry is very useful for school students in mathematics.