First choose to overlay the protractor and "stretch it to match" the curvature of the inside of the track for the "lower approach loop." As you expand the size of the protractor some of it will move off the screen. Now choose the vertical ruler and measure the radius of the original approach. After lining up the zero of the ruler with the center of the protractor, you should obtain a value close to 15.5 meters. Take a moment to note that the top of the corkscrew lies below the center of the circle created by the approaching track. This relationship will be an important consideration when constructing your conclusions.
Now move the protractor and adjust its size to match the inside track of the top of the corkscrew. The "x-axis" of the protractor should line up with the vertical trusses which are supporting the corkscrew. Now move the vertical ruler and measure the circle's radius.
Now play the video several times to acquaint yourself with the scenario that was filmed.