In an acute angle triangle ABC, AD, BE and CF are the altitudes, then `(EF)/a+(FD)/b+(DE)/c` is equal to -

In triangle ABC, AD, BE and CF are altitudes. Prove I, that, AD + BE + CF lt AB + BC + CA

In a triangle ABC, sin A- cos B = Cos C , then angle B is

If in a triangle AB=a,AC=b and D,E are the mid-points of AB and AC respectively, then DE is equal to

In triangle ABC, AD is a median. Prove that AB + AC gt 2AD

ABC is an equilateral triangle of side 2a. Find each of its altitude.

If D ,Ea n dF are three points on the sides B C ,C Aa n dA B , respectively, of a triangle A B C such that AD,BE and CF are concurrent, then show that (B D)/(C D),(C E)/(A E),(A F)/(B F)=-1

AD, BE and CF are altitudes of triangle ABC. If AD = BE = CF, prove that triangle ABC is an equilateral triangle.

In a right triangle with legs a and b and hypotenuse c, angles A,B and C are opposite to the sides a,b and c respectively, then e^(lnb-lna) is equal to-

In a right angle triangle ABC, right angle is at B ,If tan A=sqrt(3) , then find the value of (i) sin A cos C+ cos A sin C " "(ii) cos A cos C -sin A sin C

The sides of a triangle are in AP. If the angles A and C are the greatest and smallest angle respectively, then 4 (1- cos A) (1-cos C) is equal to