Question

In a $\Delta ABC$ if $\angle B$ is an obtuse angle then the longest side is__

• A. AC
• B. AB
• C. BC
• D. None of these

Answer 1

The correct option is A AC

In a $△ABC$, $\angle B$ is an obtuse angle.

Let $\angle B={120}^o$

Since, $△ABC$ contain one obtuse angle. Then, other two angles will be acute angles.

$\therefore$ $△ABC$ is an obtuse angled triangle.

$\Rightarrow$ In obtuse angled triangle, longest side is the one opposite to the obtuse angle.

$\Rightarrow$ So, side opposite to $\angle B$ is $AC$.

$\therefore$ In $△ABC$, the longest side is $AC.$