The point P(3, 6) is first reflected on the line y = x and then the image point Q is again reflected on the line y = $$-$$ x to get the image point Q'. Then, the circumcentre of the $$\Delta$$PQQ' is

Let d₁ and d₂ be the lengths of the perpendiculars drawn from any point of the line $$7x - 9y + 10 = 0$$ upon the lines 3x + 4y = 5 and 12x + 5y = 7, respectively. Then,

The line AB cuts off equal intercepts 2a from the axes. From any point P on the line AB perpendiculars PR and PS are drawn on the axes. Locus of mid-point of RS is

x + 8y $$-$$ 22 = 0, 5x + 2y $$-$$ 34 = 0, 2x $$-$$ 3y + 13 = 0 are the three sides of a triangle. The area of the triangle is