Angle at the Centre and Circumference

The centre always "sees" more

Theorem: The angle at the centre of a circle is twice the angle at the circumference, when both are subtended by the same arc - like standing right at a stadium's centre spot versus watching from the stands; the view angle differs in a fixed, predictable way.

Example: If the angle at the circumference is 35°, the angle at the centre (same arc) is 70°.

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