A circle is inscribed in an equilateral triangle of side of length 12. If the area and perimeter of any square inscribed in this circle are m and n, respectively, then m+n2 is equal to
(A)312
(B)408✓ Correct
(C)396
(D)414
Answer: (B)
Solution
An equilateral triangle of side 12 has inradius r=23a=2312=23, so r2=12. A square inscribed in this circle has diagonal 2r, so side s=22r=r2; area m=s2=2r2=24 and perimeter n=4s, so n2=16s2=32r2=384.
m+n2=24+384=408.
JEE Main · 2024 · 06 Apr 2024 · Shift 1 · Single correct option