Technical Graphics  Plane Figures  The Parabola
Rectangle Construction Method
Step
1 : Draw the rectangle you wish to construct the Parabola in, and divide it along the axis of the Parabola, to give the Vertex, (V). 

Step
2 : Divide two adjacent sides of the rectangle into an equal number of parts, (green lines). You can use as many lines as you think appropriate. It is a good idea to label the lines as you see in the diagram. 

Step
3 : Join the Vertex (V), to each of the divisions on the edge of the rectangle parallel to the axis of the Parabola, (purple lines). 

Step
4 :Finally join where each of the angled lines from the Vertex, (purple lines), cross the corresponding line which is parallel to the axis of the Parabola (green vertical lines). 

And the result is a Parabola. This method will work for any Parabola no matter what angle the axis is at so long as you have or can construct the box surrounding the Parabola. 

