1, preparation tools: prepare a piece of drawing paper, pencil, ruler and protractor.
2. Determine the starting point and ending point of the road: mark the starting point and ending point of the road on the drawing.
3. Select radius: determine the radius of the road. The larger the radius, the smoother the curve; The smaller the radius, the steeper the curve.
4. Draw a tangent: connect the starting point and the ending point with a ruler, and draw the tangent of the road, that is, a straight line segment. Make sure the tangent is long enough to fit the road curve.
5. Determine the starting point of the curve: at the starting point, select a point from the tangent as the starting point of the curve.
6. Determine the midpoint of the curve: measure the line segment at a certain angle from the starting point with a protractor, usually 90 degrees. This line segment will become the radius of the curve.
7. Draw a curve.