Geometry Q Need Help!

[slick045]

A is a point on Circle Y. BC is a chord of Circle Y with length 10. BC intersects AY at a 90 degree angle at Point D. The length of AD is 4.

What is the circumferenc of Circle Y?

[securitygeek]

Is point Y the center? Assuming it is the center, the circumference would be 6pi.

[slick045]

I don't think that is possible because chord AC is 10. A chord is equal to or smaller than the diameter of a circle. If it was the diameter (the case for the smallest circle) then the circumference would be 10pi. So the Circ. must be 10pi or greater.

The only thing I can think of is that I misinterpreted the word problem some how and that's why I can't find the answer. Thanks for your help, though!! 10 days until I retest!!

[bunny]

ans is 10.25*3.14

just apply pyth..theroem to BYD triangle
BY = r, BD = 5 ,DY = r - 4;

[slick045]

Thanks bunny, I don't know why I didn't see that!!!! I think it was the pressure of the test and all. I was hoping that there was a simple solution. Thanks again.