If `cosC=(sinB)/(2sinA)`,show that `/_\ABC` is isoscles.

If cot (A/2)=(b+c)/a.show that /_\ABC is right angled.

If sin^2A + sin^2B= sin^2 C ,show that /_\ABC is right-angled.

Show that 6+sqrt2 is irrational.

In triangle ABC, a sin A= b sin B. Show that the triangle is isosceles.

If in triangle ABC , (a^2+b^2)sin(A-B)=(a^2-b^2)sin(A+B) ,show that the triangle is either'isosceles or right angled.

If sinA =cosB , then show that A+B=90 .

In an isosceles triangle ABC if AC=BC and AB^2 = 2AC^2 , prove that /_C is a right angle.

Show that sqrt2 is an irrational number.

In /_\ABC ,a/cosA=b/cosB=c/cosC.Show that the triangle is equilateral.

ABC is an isosceles triangle with AC=BC.If AB^2=2AC^2 .prove that ABC is a right triangle.