Circle Geometry (1 Viewer)

[mtsmahia]

Hi guys,

Ive come across some many Q in Circle Geometry but im getting confused on one fact

If in the Q, it is not told that the quadilateral is cyclic, are we allowed to the exteriror angle rule ?

 

[lychnobity]

No.

 

[mtsmahia]

No.

so, if there is nothing told about the quad, we cannot assume it is cyclic

 

[lychnobity]

so, if there is nothing told about the quad, we cannot assume it is cyclic

Yes, unless they have provided a diagram and it's visible that the quad is cyclic.

 

[mirakon]

Or you can attempt to prove that said quadrilateral is cyclic via showing it's opposite angles are supplementary or Ptolemy's Theorem and then use ext angle theorem.