Question:

The area of the circle passing through the points \((5,\pm 2)\), \((1,2)\) is

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The center of a circle can be found by intersecting the perpendicular bisectors of any two chords of the circle.
Updated On: Jun 22, 2026
  • \(8\pi\)
  • \(4\pi\)
  • \(2\pi\)
  • \(16\pi\)
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The Correct Option is A

Solution and Explanation

Step 1: Identify the given points.
The given points are
\[ (5,2),\quad (5,-2),\quad (1,2) \]

Step 2: Find the perpendicular bisector of the vertical chord.
The points \((5,2)\) and \((5,-2)\) form a vertical chord.
Its midpoint is
\[ \left(5,\frac{2+(-2)}{2}\right)=(5,0) \] Therefore, the perpendicular bisector is the horizontal line
\[ y=0 \]

Step 3: Find the perpendicular bisector of another chord.
Consider the points \((5,2)\) and \((1,2)\).
This is a horizontal chord.
Its midpoint is
\[ \left(\frac{5+1}{2},\frac{2+2}{2}\right)=(3,2) \] Therefore, its perpendicular bisector is the vertical line
\[ x=3 \]

Step 4: Find the center of the circle.
The center is the intersection of the two perpendicular bisectors:
\[ x=3,\quad y=0 \] Hence, the center is
\[ (3,0) \]

Step 5: Find the radius of the circle.
Using the distance formula between the center \((3,0)\) and the point \((5,2)\),
\[ r=\sqrt{(5-3)^2+(2-0)^2} \] \[ =\sqrt{2^2+2^2} \] \[ =\sqrt{4+4} \] \[ =\sqrt{8} \] Thus,
\[ r^2=8 \]

Step 6: Calculate the area of the circle.
Area of a circle is
\[ \pi r^2 \] Therefore,
\[ \text{Area}=\pi(8) \] \[ =8\pi \]

Step 7: Final conclusion.
Hence, the area of the circle is
\[ \boxed{8\pi} \]
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