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Discover the beautiful relationships within circles
Central angle = 2 × Inscribed angle
Perpendicular from center bisects chord
Tangent ⊥ radius at point of tangency
Inscribed angles on same arc are equal
Relationship
The central angle (120°) is exactly twice the inscribed angle (60°)!
Drag the yellow point around the circle. Watch how the inscribed angle changes while staying half of the central angle!
Challenge
Make the inscribed angle exactly 45°
Score
0
Streak
If you move the inscribed angle point to create a 30° inscribed angle, what will the central angle be?
Correct!
You've discovered the inscribed angle theorem!