9.5+(WiBr56)

__Theorem__ If two segments are tangent to a circle from the same external point, then the segments are of equal length.

__Theorem__ If two secants intersect outside a circle, the product of the lengths of one secant and its external segment equals the product of the lengths of the lengths of the other secant segment and its external segment. (whole x outside = whole x outside)

__Theorem__ If a secant and a tangent intersect outside a circle, then the product of the lengths of the secant segment and its external segment equals the length of the tangent segment squared. (whole x outside = tangent squared)

__Theorem__ If two chords intersect inside a circle, then the product of the lengths of the segments of one chord equals the product of the lengths of the segments of the other chord.



__Example__

(whole x outside) = (whole x outside) (20 x 2) = (X x 4) __40__ = __4x__ 4x 4x 10 = x
 * Find the length of X**