if two trangles segments are down from
the same external point, then segment are equal
Answers
Tangent Segments
Given a point outside a circle, two lines can be drawn through that point that are tangent to the circle. The tangent segments whose endpoints are the points of tangency and the fixed point outside the circle are equal. In other words, tangent segments drawn to the same circle from the same point (there are two for every circle) are equal.
Figure %: Tangent segments that share an endpoint not on the circle are equal
Chords
Chords within a circle can be related many ways. Parallel chords in the same circle always cut congruent arcs. That is, the arcs whose endpoints include one endpoint from each chord have equal measures.
Figure %: Arcs AC and BD have equal measures
When congruent chords are in the same circle, they are equidistant from the center.
Figure %: Congruent chords in the same circle are equidistant from the center
In the figure above, chords WX and YZ are congruent. Therefore, their distances from the center, the lengths of segments LC and MC, are equal.