A rectangle R with end points of one of its sides as (1,2) and (3,6) is inscribed in a circle. If the equation of a diameter of the circle is 2x−y+4=0, then the area of R is ______.
Answer: 16
Solution
The side AB has endpoints (1,2) and (3,6). The equation of line AB is:
x−1y−2=3−16−2=2⇒y=2x
The given diameter has equation 2x−y+4=0, or y=2x+4, which has slope 2.
Since the diameter is parallel to AB (both have slope 2), the perpendicular distance between them gives half the width of the rectangle:
d=22+12∣4∣=54
So the width BC=2d=58.
The length AB=(3−1)2+(6−2)2=4+16=25.
Area =AB×BC=25×58=16.
JEE Main · 2022 · 27 Jun 2022 · Shift 1 · Integer answer