Special Angles and Arcs in Circles: Introduction

The Dom Luis I Bridge in Portugal

The image you see here of the Dom Luis I bridge in Portugal and is a great image of special segments in circles.  The upper road on the bridge is tangent to the curved support.  The lower road of the bridge crosses the curved support in two places, making it  secant to the curve.  In this section, you will learn about these different segments and the measures of the angles made by different type of segments.