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MHT CET · Maths · Properties of Triangles

In \(\triangle A B C\), if \(\frac{\cos A}{a}=\frac{\cos B}{b}=\frac{\cos c}{c}\) with usual notations, then the triangle is

  1. A an isosceles triangle
  2. B an equilateral triangle
  3. C a right angled scalene triangle
  4. D a scalene triangle
Verified Solution

Answer & Solution

Correct Answer

(B) an equilateral triangle

Step-by-step Solution

Detailed explanation

From sine rule \(a / \sin A=b / \sin B=c / \sin C=2 R\)
Given situation
\(a / \cos A=b / \cos B=c / \cos B=k\)
\(2 R \sin A=k \cos A\)
\(\tan A=\tan B=\tan C\)
Hence it is equilateral triangle.