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Inscribed angles


A circle is centered on point B. Points A, C and D lie on its circumference.
If ABC measures 40, what does ADC measure?
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
A circle centered at point B. Points A, D, and C all lie on the circle in a clockwise direction. Segments A B and C B are both radii of the circle. There is a chord connecting points C and D. There is another chord connecting point A and D. The two chords create an irregular quadrilateral with angle A D C inside of it. A symbol highlights angle A B C. Another symbol highlights angle A D C.