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The arc determined by angle
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The measures of ![]() ![]() |
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Also, note ![]() ![]() |
Consequently, ![]() ![]() |
Because triangles ![]() ![]() ![]() |
Ratios of corresponding sides are equal, so |
CD/CA = CE/CB. |
and |
CD*CB = CA*CE |
That is, for any point C outside a circle, and any line through C intersecting the circle in
two points, P and Q (B and D, or A and E in the figure),
the product |
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