Inscribed quadrilateral and eccentric angles
Analysis 1
Change the positions of points A, O or V and note the angles and the sums. What can you notice?
Proof
Internal Eccentric Angle
Analysis 2
Enable the "Show / Hide central angles" and "Show / Hide the half sum of angles" boxes. Change the positions of points A, C or B and compare the inner eccentric angle with the result of the half sum. What can you notice?
Proof
External Eccentric Angle
Analysis 3
Enable the "Show /Hide central angles" and "Show / Hide half of the absolute value of the angle difference "boxes. Change the positions of points A, B, C or D and compare the external eccentric angle with the result of the difference. What can you notice?
Challenge
Explain the property.