Can someone please help me with this? The lesson explains it, but I just don't get it.....

Jerry inscribed a quadrilateral ABCD in a circle, as shown below.
http://learn.flvs.net/webdav/assessment_images/educator_geometry_v14/pool_Geom_3641_0800_Subtest_01_06/image0024e67730b.jpg
If the measure of arc BCD is 250°, what is the measure of angle BCD?

Question

Can someone please help me with this? The lesson explains it, but I just don't get it.....

Jerry inscribed a quadrilateral ABCD in a circle, as shown below.
http://learn.flvs.net/webdav/assessment_images/educator_geometry_v14/pool_Geom_3641_0800_Subtest_01_06/image0024e67730b.jpg
If the measure of arc BCD is 250°, what is the measure of angle BCD?

anonymous · Answer

@amistre64 @phi

amistre64 · Answer

cant link directly to flvs

anonymous · Answer

It's from the lesson...

amistre64 · Answer

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amistre64 · Answer

notice that the angle at c ison the edge of the circle; there is a property that says this angle is half the arc across from it

anonymous · Answer

where does the 250 come from?

amistre64 · Answer

BCD = 250 is stated in the question ....

anonymous · Answer

The inscribed quadrilateral theorem?

anonymous · Answer

okay

amistre64 · Answer

i got no idea what its spose to be called :)

anonymous · Answer

okay haha

anonymous · Answer

I got 10 and 5 when I solved the part you wrote....... @amistre64

amistre64 · Answer

360-250 is the arc that angle BCD is facing soo; BCD = (360-250)/2 = 110/2 = 55 to me

anonymous · Answer

ohhhhhhhhhhhhhhhhhhhh okay, so it's 55 because it's half of the opposite arc?