Exploring Tangent Lines to Circles

Part 1: Tangents and Angles
In the graph, the line shown is tangent to the circle at point C. [br][br]Move point D around and note how the angle between the tangent line and segment CD changes.
Make the angle a RIGHT angle!
Move point D until the angle is a right angle. (Be sure to click and drag point D).[br][br]What is true about segment CD when the angle measure is 90 degrees?
Part 2: What is true about two intersecting tangents to a circle?
In the graph shown, the circle has two tangent lines that intersect. Look closely at the pink line segments (CG and FG) .[br][br][color=#ff0000][b]Answer the question below BEFORE clicking to show the lengths of the segments.[/b][/color]
What appears to be true about the lengths of segments CG and FG? Once you answer, click to show the lengths. Also, try moving points C and F around.
Fechar

Informação: Exploring Tangent Lines to Circles