If in a ΔABC, cosAa=cosBb=cosCc, then what can be said about the triangle?
Equilateral triangle
Since rule says that = asinA=bsinB=csinC=k
Therefore, a=k(sinA), b=k(sinB) and c=k(sinC)
We can write cosAa=cosBb=cosCc as
cosAksinA=cosBksinB=cosCksinC = cot A=cot B=cot C
⇒ A=B=C(Equilateral Triangle).