Hello, dgenerationx2!

Here's #19 . . .

Let19. is tangent to the circle and is a secant.

. . . FindCode:B x * * * - - - - - - * A * * / * * / 4 * * D / * / * * / * * / 5 * / * / * * / * * * C * * *

Theorem:

If a tangent and a secant are drawn to a circle from an external point,

the tangent is the mean proportional between the external segment

of the secant and the entire secant.

Hence: .

Therefore: .