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Circles SAT question
Math · Geometry and Trigonometry · Hard · Answer it here, explanation included.
The equation 
defines a circle in the xy‑plane. What is the radius of the circle?
Enter a number or fraction (like 3/17 or 0.176). Press Enter to check.
ExplanationShow
The correct answer is 11. A circle with equation 
, where a, b, and r are constants, has center 
and radius r. Therefore, the radius of the given circle is 
, or 11.
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