MHB Prove Geometry Challenge: Cyclic Quadrilateral PQRS

anemone
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Given a cyclic quadrilateral $PQRS$ where $PQ=p,\,QR=q,\,RS=r$, $\angle PQR=120^{\circ}$ and $\angle PQS=30^{\circ}$.

Prove that $|\sqrt{r+p}-\sqrt{r+q}|=\sqrt{r-p-q}$
 
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anemone said:
Given a cyclic quadrilateral $PQRS$ where $PQ=p,\,QR=q,\,RS=r$, $\angle PQR=120^{\circ}$ and $\angle PQS=30^{\circ}$.

Prove that $|\sqrt{r+p}-\sqrt{r+q}|=\sqrt{r-p-q}$

my solution :

View attachment 4127
 

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Thank you Albert for your solution:cool: and I will post the answer that I have at hand later, in case there are others who might want to try it..
 
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