Coordinate Geometry Question 45

Question: If the points (1,1) (-1,-1) $ (-\sqrt{3},\sqrt{3}) $ are the vertices of a triangle, then this triangle is

[MP PET 2004]

Options:

A) Equilateral

B) Right-angled

C) Isosceles

D) None of these

Show Answer

Answer:

Correct Answer: A

Solution:

Given, vertices of triangle are $ A(1,1),B(-1,-1) $ and $ C(-\sqrt{3},\sqrt{3}) $ Now, $ AB=\sqrt{{{(-1-1)}^{2}}+{{(-1-1)}^{2}}}=\sqrt{4+4}=\sqrt{8} $

$ BC=\sqrt{{{(-\sqrt{3}+1)}^{2}}+{{(\sqrt{3}+1)}^{2}}}=\sqrt{8} $

$ CA=\sqrt{{{(1+\sqrt{3})}^{2}}+{{(1-\sqrt{3})}^{2}}}=\sqrt{8} $ i.e., $ AB=BC=CA $ . So, it is an equilateral triangle.