Ellipse problem
Geometry
Level
2
A and B are the two foci of the ellipse, and CD is tangent to the ellipse at point C.
Find the measure of angle CDA in degrees.
The answer is 20.
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By the reflective property of ellipses, the angle DCA is the same as the angle BCE (er E be the ''Endpoint" of the line).
So DCA equals ( 180 - 60 ) /2 = 60.
DAC = 180 - 80 = 100.
So the angle ADC = 180 - 100 - 60 = 20