In triangle `A B C ,b^2 sin2C+c^2sin2B=2bc where b=20 ,c=21 ,` then inradius= (a)4 (b) 6 (c) 8 (d) 9

In a triangle ABC, prove that b^(2) sin 2C+c^(2) sin 2B=2bc sin A .

In any triangle ABC ,c^2 sin 2 B + b^2 sin 2 C is equal to

In a triangle ABC, sin^(2)A + sin^(2)B + sin^(2)C = 2 , then the triangle is

In any triangle A B C ,(a^2+b^2+c^2)/(R^2) has the maximum value of (a) 3 (b) 6 (c) 9 (d) none of these

If sides of triangle A B C are a , ba n dc such that 2b=a+c then b/c >2/3 (b) b/c >1/3 b/c<2 (d) b/c<3/2

In triangle A B C ,2a csin(1/2(A-B+C)) is equal to a^2+b^2-c^2 (b) c^2+a^2-b^2 (c) b^2-c^2-a^2 (d) c^2-a^2-b^2

In triangle A B C , let /_c=pi/2dot If r is the inradius and R is circumradius of the triangle, then 2(r+R) is equal to (a) a+b (b) b+c (c) c+a (d) a+b+c

In triangle A B C , let /_c=pi/2dot If r is the inradius and R is circumradius of the triangle, then 2(r+R) is equal to a+b (b) b+c c+a (d) a+b+c