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Show that the the triangle is isosceles
By alpha
Created 07/23/2009 - 15:13

In a triangle ABC,if$ Cos A=\frac{sinB}{2sinC} $, then show that the the triangle is isosceles.

$$\frac{b^2+c^2-a^2}{2bc}=\frac{2R\sin B}{4R\sin C}=\frac{b}{2c}$$
$$c^2=a^2$$
$$c=a$$
‹ Find the value of : [1] Prove that › [2]
Source URL: http://www.9math.com/forum/show-triangle-isosceles

Links:
[1] http://www.9math.com/forum/find-value-%253A-2
[2] http://www.9math.com/forum/prove-23