if in triangle ABC, tanA + tanB + tanC > 0, then a)triangle is obtuse angled b)triangle is always acute angled c)triangle is always equilateral d)nothing can be said Share with your friends Share 0 Rahul Raj answered this Dear student In a triangleA+B+C=πA=π-B-CtanA=tan(π-B-C)=-tan(B+C)=-tanB+tanC1-tanBtanCtanA-tanAtanBtanC=-tanB-tanCtanA+tanB+tanC=tanAtanBtanCtanA+tanB+tanC>0tanAtanBtanC>0in a triangle atmost one angle can be obtuse and tan will be negativeproduct of tan will be negativebut if product is positive, all three angles are acuteso in this case, it is an acute angled triangle Regards -3 View Full Answer