Crossing Chords: Proof Hint
In the applet below, 2 intersecting chords are drawn within a circle.
Interact with the applet below for a few minutes, then answer the questions that follow.
1.
What do you know about the measures of the pink angles?
2.
Why is your response to (1) true?
3.
What do you know about the measures of the blue angles? Why is this?
4.
Given your responses to (1) & (3) what can you conclude about the two triangles?
5.
Use your response to (4) to write a relationship (equation) among the lengths a, b, c, and d.
6.
Rewrite your equation in (5) above so that both sides of the equation are written as products instead of ratios. What do you get?