Q.

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                                [2024]

1 396  
2 408  
3 414  
4 312  

Ans.

(2)

Let radius of inscribed circle be r.

r=13AD

=13a2-a24,  a is side of triangle.

=a23=1223=23

Area of square DEFG, m=12×(diagonal)2

        =12×(2r)2=12×4×12=24 sq. units

Side of square =26

Perimeter of square, n=4×26=86

  m+n2=24+384=408