If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

Inscribed angles

Problem

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.
Stuck?
Stuck?