If you prefer to hear the voiceover of this lesson, go to the “Links” tab on my webpage and open up the “Segments of Circles” link.

a b c d ab = cd

9 2 6 x X = x X = x X = 1 Example 1:

Example 2: Find x x 3x 2x  3x = 12  8 6x 2 = 96 x 2 = 16 x = 4

EAB C D EA EB = EC ED

E A B C D x 7(7 + 13) 4(4 + x) = Example 3: 140 = x 124 = 4x x = 31

E A B C D x 6(6 + 8) 5(5 + x) = Example 4: 84 = x 59 = 5x x = 11.8

Tangent Segment Secant Segment External Segment Notice that on the tangent segment, the outside is the whole!

E A B C EA 2 = EB EC

E A B C x 24 2 =12 (12 + x) 576 = x x = 36 Example 5:

E A B C 15 5 x x2x2 =5 (5 + 15) x 2 = 100 x = 10 Example 6:

What you should know by now… Given two chords Given two secants OR a tangent and a secant