Answer :

The point of intersection of two diameters is the centre of the circle.

The point of intersection of two diameters x – y = 9 and x – 2y = 7 is (11, 2).

∴ Centre = (11, 2)

Area of a circle = π r²

38.5 = π r²

r² = 39.5 / π

r² = 12.25 sq.cm

The equation of the circle is,

(x – h)² + (y – k)² = r²

(h, k) is the centre of the circle and r is the radius of the circle.

(x – 11)² + (y – 2)² = 12.25