Two chords AB and CD of a circle meet when produced outside the circle at P.

AD and BC are joined.If |_ PAD =30 and |_ CPA is 45, then |_ CBP will be

105

115

135

145

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- Aug 19th 2008, 10:23 PMdeviCircles n chords.
Two chords AB and CD of a circle meet when produced outside the circle at P.

AD and BC are joined.If |_ PAD =30 and |_ CPA is 45, then |_ CBP will be

105

115

135

145 - Aug 19th 2008, 10:31 PMo_O
Notice that $\displaystyle \angle PAD = \angle BCD$ because the both subtend from the

**same**arc BD.

Now, if you look at $\displaystyle \triangle CBD$ as a triangle, you'll see that you have 2 of the 3 angles. The missing angle is what you're looking for and can be easily found since you know that the angles must add up to 180 degrees.