In the triangle ABC, if the angle a = 120 degrees, ab = 4, AC = 2, then SINB =?
14/√21
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- 2. As shown in the figure, in the triangle ABC, the angle BAC is equal to 90 degrees, ad is perpendicular to BC, and BD square = BD times BC
- 3. Take any point O in the triangle ABC, connect Ao, Bo, CO respectively, and extend the opposite edge to a ', B', C '. Prove: OA' / AA '+ ob' / BB '+ OC' / CC '= 1
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- 11. In the triangle ABC, the angle a = 120 °, ab = 4, AC = 2, then the value of SINB is () Originally there was no picture
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- 19. It is known that: as shown in the figure, in △ ABC, the bisector am of ∠ C = 90 °, BAC = 60 ° is 15cm, and the length of BC is calculated
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