Question

Consider a circle C which touches the y-axis at (0, 6) and cuts off an intercept 6 √5 on the x-axis. Then the radius of the circle C is equal to : 

(1) √53 

(2) 9 

(3) 8 

(4) √82

Answer 1

r = \(\sqrt{6^2 + (3\sqrt{5})^2}\)

= \(\sqrt{36+ 45}\) = 9