### Home > A2C > Chapter 11 > Lesson 11.2.3 > Problem 11-69

11-69.

Find the equation of the ellipse you would form using the same process as in problem 11-65 but with a string 15 units long.

**Extra challenge:** See how far you can get rewriting it to fit the form of your result from problem 11-65.

Remember that the length of the string is the sum of the distances from each of the foci to any point on the ellipse.