Question

Circumcentre of the triangle formed by the line y = x, y = 2x and y = 3x + 4 is

• A. (6, 8)
• B. (6, - 8)
• C. (3, 4)
• D. (- 3, - 4)

Answer 1

The correct option is B

(6, - 8)

$x^2+y^2=(x+4{)}^2+(y+8{)}^2$ $\Rightarrow$ 8x + 16y + 80 = 0

and $x^2+y^2=(x+2{)}^2+(y+2{)}^2$ $\Rightarrow$ 4x + 4y + 8 = 0

On simplification, we get y = -8 and x = 6.