Hi fren,
x=<span><span>−y</span>+<span>1
and for the second one...
</span></span>y=<span><span>2x</span>+<span>2
</span></span>x-intercept >> <span>(<span><span>−1</span>,0</span>)
</span>y-intercept >> <span>(<span>0,2)</span></span><span>
</span>
The circumference formula is pi times diameter. So first divide 56.52 by 3.14 and that is 18. So the diameter is 18
