Question

If a,b,c are sides of DABC and $\left| \begin{matrix} a^{2} & b^{2} & c^{2} \\ (a + 1)^{2} & (b + 1)^{2} & (c + 1)^{2} \\ (a - 1)^{2} & (b - 1)^{2} & (c - 1)^{2} \end{matrix} \right|$

= 0 , then –

• A. ABC is an equilateral triangle
• B. ABC is right angled triangle
• C. ABC is an isosceles triangle
• D. None of these

Answer 1

Answer: (C)

ABC is an isosceles triangle

Answer 2

When a = b or b = c or c = a, the determinant reduces to zero .

It is not necessary that a = b = c for determinant to be zero. Therefore triangle is isosceles