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Answer:
7.
radius [r]=3in
length of bold part of circle=(360-40°)/360×2πr
=8/9×2×π×3=16.755
8.
we have
x²-2=2-y²
x²+y²=4..........(1)
comparing above equation with
(x-h)²+(y-k)²=r²
we get
centre(h,k}=(0,0)
radius [r]=2 units