Question

If the points (0, 1, 2), (2, –1, 3) and (1, –3, 1) are the vertices of a triangle, then the triangle is

• A. Right angled
• B. Isosceles right angled
• C. Equilateral
• D. None of these

Answer 1

The correct option is B

Isosceles right angled

Here $a=\sqrt{4+4+1}=\sqrt{9},b=\sqrt{1+4+4}=\sqrt{9}andc=\sqrt{1+16+1}=\sqrt{18}.$
We can see it is a right angled and isosceles triangle.