Question 1040661: Find the equation of the circle if a triangle whose sides lie on the lines 3x+4y=8, 3x-4y=32 and x-8=0 inscribed the circle.
Answer by Fombitz(32388) (Show Source):
You can put this solution on YOUR website! Find the intersection points.
From eq. 3,

Substituting into eq. 1,




(8,-4)
Substituting into eq. 2,




(8,-2)
Finally adding eq. 1 and eq. 2,




So,




(20/3,-3)
Now you have three points on the circle, solve for the circle.
Use the general form,

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(8,-4):


4.
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(8,-2):


5.
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(20/3,-3):



6.
Subtracting eq. 5 from eq. 4,



Substituting into eq. 4,

7.
Substituting into eq. 6,

8.
Multiply eq. 7 by -9 and add to eq. 8,



and substituting into eq. 7,




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You can complete the square to get into center-radius form,





Center : ( , )
Radius : 
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