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In triangle ABC, angle B is a right angle. BD is the altitude. r1, and r2, are the inradii of the triangles ADB, and BDC respectively, the points E, F, and G are points of tangency. Prove that .

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Prove the following: if, in a triangle ABC,  mÐ BAO = mÐ OAC = 20°, mÐ ACO = 10°,and mÐ OCB = 30°, then mÐ OBC = 80°.

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Prove the following: if, in a triangle ABC, median BD is such that mÐ A = mÐ DBC, and mÐ ADB = 45°, then mÐ A = 30°.


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http://www.unl.edu/amc/mathclub/04,2b-q,MWorld.html

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