A rectangle is inscribed in a circle with a diameter lying along the line 3y=x+7. If the two adjacent vertices of the rectangle are (−8,5) and (6,5) then the area of the rectangle (in sq. units) is
(A)72
(B)84✓ Correct
(C)98
(D)56
Answer: (B)
Solution
The two given vertices (−8,5) and (6,5) share the same height, so that side is horizontal with length 14. The rectangle is inscribed in the circle, so the circle's centre is where the diagonals meet and lies on the given diameter line 3y=x+7. The centre's x-coordinate is the midpoint of the horizontal side, x=−1; putting this on the line, 3y=−1+7=6, so y=2 and the centre is (−1,2). Since the centre's height is the average of the top and bottom sides, the other pair of vertices sits at y=−1, making the vertical side ∣5−(−1)∣=6. The area is 14×6=84 square units.Diagram showing rectangle inscribed in circle
JEE Main · 2019 · 09 Apr 2019 · Shift 2 · Single correct option