Need help with circular geometry (1 Viewer)

[thunda]

how can i find x? i asked a couple of people and they told me that there is not enough info to work out x... don't know if this is true but.
btw- I Found this in the fitzpatrick 3u textbook.

 

[abcd9146]

not possible, the answers says its 109 degrees, but there is no way to prove it

 

[SoulSearcher]

I tried doing that question for a while, but there is no way to prove that the angle is 109 degrees without a bit more information.

 

[Irradiated]

this is the best answer i could come up with, i got help from a physics teacher, no one in maths knew how to do it

 

[Riviet]

Sorry to say this, but how do you know that the diameter is parallel to the chord?

 

[SoulSearcher]

this is the best answer i could come up with, i got help from a physics teacher, no one in maths knew how to do it

You cannot assume that a cyclic quadralateral has parallel sides, until you prove that the co-interior angles are supplementary, which you have seemed to have mixed up with the theorem that the opposite angles of a cyclic quadraleteral are supplementary.

 

[YBK]

That is messed up...

all I could get was that the angle at the circumfrence is half angle at centre which means angle at centre is 2x. then we have 2 opposite angles half each other and 2 equal sides.

bah.

 

[Riviet]

Another thing I noticed about the diagram is if you take the bottom radius and the bottom left chord, you can stretch and move them around the bottom side of the circle and would produce many differerent angles. Therefore we have not been given enough information to be able to make find a definite angle of x.