You have to divide both 9 & 6 by their greatest common factor which is 3 so the answer is 3
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2
1) Because
is a central angle,
.
Since
and
are supplementary, they form a linear pair, and thus 
5) Tangents drawn from an external common point are congruent, so CR=CP=8 and RB=BQ=4. This means that QA=11, and so PA=11 as well. Adding CP+PA, we get AC=19.
6) By the inscribed angle theorem, angle QPR measures 36 degrees.
I think it may be (6/7)^2