http://www.ck12.org Chapter 9. Circles
Example B
Find the value of the missing variable.
Use the Two Secants Segments Theorem to set up an equation. For both secants, you multiply the outer portion of
the secant by the whole.
x·(x+x) = 9 · 32
2 x^2 = 288
x^2 = 144
x= 12x 6 =−12 because length cannot be negative.
Example C
True or False: Two secants will always intersect outside of a circle.
This is false. If the two secants are parallel, they will never intersect. It’s also possible for two secants to intersect
inside a circle.
Watch this video for help with the Examples above.
MEDIA
Click image to the left for use the URL below.
URL: http://www.ck12.org/flx/render/embeddedobject/52429CK-12 Foundation: Chapter9SegmentsfromSecantsB
Concept Problem Revisited
The given information is to the left. Let’s set up an equation using the Two Secants Segments Theorem.