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Inscribed shapes


Angle C is inscribed in circle O.
AB is a diameter of circle O.
What is the measure of A?
  • Your answer should be
  • an integer, like 6
  • an exact decimal, like 0.75
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
A circle centered at point O. Points A, B, and C all lie on the circle in a clockwise direction. A line segment connects point A to point B as a diameter. A line segment B C is a chord. Line segments O A and O B are radii. Angle C B O is sixty degrees.