A. Δ
B. 3Δ
C. 2Δ
D. 4Δ
In ΔABC, if cos2 A+cos2B+ cos2C=3/4, then the triangle is
The angle of elevation of the summit of a mountain at a point A is 450. After walking 200 mt from A towards the mountain along a road included at 150, it is observed that the angle of elevation of the summit is 600. The height of the mountain is
In ΔABC, if sin A: sin C = sin (A-B) :sin (B-C), then a2,b2,c2 are in
In a triangle ABC, (a2-b2-c2) tan A+ (a2-b2+c2) tan B is equal to
In ΔABC, r12+r22+r32+r2 =
A man observes that angle of elevation of the top of a tower from a point P on the ground is θ. He moves a certain distance towards the foot of the tower and finds that the angle of elevation of the top has doubled. He further moves a distance 3/4 of the previous and finds that the angle of elevation is three times that at P. Then angle θ is given by
If a. cos (θ+ α)= b cos (θ-α), then (a+b) tan θ=
If α,β are solutions of a cos 2θ+b sin 2θ=c, then tan α tan β=
If sin A= sin2 B and 2 cos2 A =3 cos2 B, then the ΔABC is
In ΔABC, if A=900 then r2 +r3 =