यदि A,B और C त्रिभुज ABC के अन्तः कोण हो तो दिखाइए कि `sin""(B+C)/(2)=cos""(A)/(2).`

In triangle ABC , AD bisects angle A and intersects BC at D. If BC = a ,AC = b and AB = c, then BD = ? त्रिभुज ABC में, AD कोण A को समद्विभाजित करता है तथा BC को D पर काटता है | यदि BC = a, AC = b और AB = c है, तो BD = ?

In triangle ABC ,AD bisects angle A which meets BC at D. If BC = a, AC = b and AB = c, then DC = ? त्रिभुज ABC में, AD कोण A को द्विभाजित करता है जो BC से D पर मिलता है | यदि BC = a, AC = bऔर AB = c है, तो DC = ?

In a Delta ABC, prove that a ( cos B + cos C) = 2 (b + c) sin^(2)""(A)/(2)

angle A,angleB , angle C are three angles of a triangle. If angle A-angle B=15^@, angle B- angle C=30^@ , then angle A,angleB and angle C are- angle A,angleB , angle C एक त्रिभुज के तीन कोण है। यदि angle A-angle B=15^@ हो और angle B- angle C=30^@ तो angle A,angleB तथा angle C के मान क्या होंगे?

In triangle ABC,a,b,c are the lengths of its sides and A,B,C are the angles of triangle ABC .The correct relation is given by (a) (b-c)sin((B-C)/(2))=a(cos A)/(2) (b) (b-c)cos((A)/(2))=as in(B-C)/(2)(c)(b+c)sin((B+C)/(2))=a(cos A)/(2)(d)(b-c)cos((A)/(2))=2a(sin(B+C))/(2)

If the sides a,b and C of o+ABC are in A.P.,prove that 2sin(A)/(2)sin(C)/(2)=sin(B)/(2)a cos^(2)(C)/(2)+cos^(2)(A)/(2)=(3b)/(2)