Q.

Let (5,a4) be the circumcenter of a triangle with vertices A(a,-2), B(a,6)  and C(a4,-2). Let α denote the circumradius, β denote the area, and γ denote the perimeter of the triangle. Then α+β+γ is              [2024]

1 62  
2 60  
3 30  
4 53  

Ans.

(4)

The circumcentre of the triangle ABC is O(5,a4)       ∵  OA2=OB2

⇒(5-a)2+(a4+2)2=(5-a)2+(a4-6)2

⇒4a=32⇒a=8

∴   A≡(8,-2), B≡(8,6) and C≡(2,-2)

AC=36+0=6, BC=36+64=10, AB=64=8

Perimeter, γ=6+10+8=24

Circumradius, α=OA=9+16=5

Area, β=12×6×8=24

∴   α+β+γ=5+24+24=53