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The measure of ADC is 200 degrees, and lines AB and BC are tangent to this circle. What is the measure of angle ECA?

The measure of ADC is 200 degrees and lines AB and BC are tangent to this circle What is the measure of angle ECA class=

Respuesta :

Answer:

m∠ECA = 10°

Step-by-step explanation:

measure of arc AC is 360 - 200 = 160

arc AC is bisected by BE so the measure of the intercepted arc of angle BEC is 80.  Then m∠BEC = 80 since it is a central angle.  The angles formed by BE intersecting AC are right angles.  So, m∠ECA = 90 - 80 = 10

It would have been a lot easier to explain this if they had labeled the point of intersection of BE and AC