Question

Consider a circle with radius r. Tangents are drawn to it from an external point such that tangents are perpendicular to each other. All points from which such tangents can be drawn are connected by a smooth curve. M and N are any two points on that curve. What can be the maximum length of MN?

• A. 2$\sqrt{2}$ r
• B. $\sqrt{2}$ r
• C. 3$\sqrt{2}$ r
• D. 4r

Answer 1

The correct option is A 2$\sqrt{2}$ r

The correct answer is option (A).
MN${}_{max}$ = 2$\times \sqrt{r^2+r^2}$ = 2$\sqrt{2}$ r
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