ACCESS - Secant and Tangent 2
Line CD is tangent to circle O. Line AB is a secant of circle O. Drag A, B, and C to adjust the lines. The spreadsheet to the right shows the value of the measures of the arcs and angles in the circle.
1. How is the measure of angle BAC related to the purple arc AB?
2. How is the measure of angle BAD related to the green arc AB?
3. Show the radii OA and OB. How would angle AOB relate to angle CAB?
4. Hide the radii again. What is the only way that angles BAC and BAD can be equal?