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65 Points - I have class in 1hr and I still can't figure this out... pls give full explanation and correct answer or else you'll be reported for "point greediness" --- thx ya'll

AB is tangent to the circle k(O) at B, and ADis a secant, which goes through O. Point O is between A and D∈k(O). Find m∠BAD and m∠ADB, if measure of arc BD is 110°20'.

User Seanjacob
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1 Answer

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Sounds like the situation in the sketch below...

There is a theorem that says the angle (BAD) formed by a tangent (AB) and a secant (AD) to a circle (O) is half the difference of the intercepted arcs (BD and BD'):


m\angle BAD=\frac{110^\circ20'-69^\circ40'}2=40^\circ40'

Triangle BAD is a right triangle, so


m\angle ADB=90^\circ-m\angle BAD=49^\circ20'

65 Points - I have class in 1hr and I still can't figure this out... pls give full-example-1
User Mukus
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