Points A, B, C and D all lie on the circumference of the circle. Some of the points are connected by chords as shown. Point I is the intersection of chord CB and AD.[br][br]What do you notice about [math]\angle CAD[/math] and [math]\angle CBD[/math]?[br][br]Move around points C and D. What impact does this have on the two angles?[br][br]Can you infer the relationship between [math]\angle ACB[/math] and [math]\angle ADB[/math]? [br]Mark the check box and move around the points to confirm the relationship between the two angles.[br][br][br]Given what you know about the angles, what can you deduce about [math]\bigtriangleup ICA[/math] and [math]\bigtriangleup IDB[/math]?