Question

In $\Delta ABC$, if $a\cos A=b\cos B$, then the triangle is

• A. Isosceles
• B. Right angled
• C. Isosceles or right angled
• D. Right angled isosceles

Answer 1

The correct option is A Isosceles

$a\cos A=b\cos B$ Given

$2R\sin A\cos A=2R\sin B\cos B$

$2\sin A\cos A=2\sin B\cos B$

$\sin 2A=\sin 2B$

$2A=2B$

$A=B$

An Isosceles triangle is a triangle with two equal sides are equal.