Question

A triangle is formed by the lines $2x-y+1=0,3x+y-2=0andx+y-5=0$. Triangle is

• A. Equilateral triangle
• B. Acute angled triangle
• C. Obtuse angled triangle
• D. Right angled triangle
• E. Isosceles triangle

Answer 1

Answer: (C)

Obtuse angled triangle

$2>-1>-3$
$m_1>m_2>m_3$
$\tan A=\frac{2+1}{1-2}=-3$
$\tan B=\frac{-1+3}{1+3}=\frac{1}{2}$
$\tan C=\frac{-3-2}{1-6}=1$
Since $\tan A$ is negative, the triangle is obtuse angled triangle.