Recall the Secant Segments Theorem. Compare the exterior segment and the whole segment when one of the segments is tangent.
See solution.
Practice makes perfect
When two secants intersect in the exterior of a circle, the product of one secant segment and its external secant segment is equal to the product of the measures of the other secant and its external secant segment.
When a secant and a tangent intersect, the product on the left-hand side becomes the square of the length of the exterior segment because the exterior segment and the whole segment are the same segment.
