Sekirov Dictionary

director circle

UK /dɪˌɹɛk.tə ˈsɜː.kəl/US /dɪˌɹɛk.təɹ ˈsɜɹ.kəl/

noun1

  1. A circle formed by all 90° crossings of tangents of an ellipse or hyperbola.
forms

director circles

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