Math Is Fun Forum

harrychess

Member

Registered: 2014-04-04

Posts: 33

Angles In Circles

Triangle ABC is inscribed in the circle and AC = AB. The measure of angle BAC is 42 degrees and segment ED is tangent to the circle at point C. What is the measure of angle ACD? I know the formulas, but I don't know how to get angle ACD. Can someone help me?

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Angles In Circles

hi harrychess,

The formula you need is here:

http://www.mathisfunforum.com/viewtopic.php?id=17799

post #7

That makes angle ACD = angle ABC

[note: The wording doesn't say which way round to put D and E.  I've put D closer to A and E closer to B, on my diagram.)

Bob

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