[b][size=150][color=#0000ff]Secant lines intersect a circle at two points.[/color][/size][br][br]Activity Directions: Move points D, C, B, and E to discover the relationship between the measure of the angle created by two secant lines and the measures of the intercepted arcs. [/b]
What happens if you add arc CB and arc DE?
What happens in you subtract arc CB from arc DE?
Do you see a relationship between either the sum of the 2 arcs or a relationship between the difference in the arcs? If so, what do you notice?
Click on A and move it around the circle. Determine the measure Arc AB. Determine the measure of arc DE.[br][br]Try to figure out the relationship between the 2 arcs and the angle.
What happens if you add arc AB and arc DE?
What happens in you subtract arc DE from arc AB?
Do you see a relationship between either the sum of the 2 arcs or a relationship between the difference in the arcs? If so, what do you notice?
What happens if you have 2 tangent lines? Move point B around the circle.[br]
What's the measure of arc BFC?
What's the measure of arc CB?
How many arcs are present when you have 2 tangent lines?
What happens when you add the 2 angles together?
Do you see a relationship between the two arcs and the angle created by the tangents?