

InterviewSolution
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The points A(1, 5), B(2, 3) and C(-2, -1) are A) vertices of a right-angled triangle B) vertices of an isosceles triangle C) collinear D) non-collinear |
Answer» Correct option is (D) non-collinear Giver points are A(1, 5), B(2, 3) and C(-2, -1). \(\therefore\) \(AB=\sqrt{(2-1)^2+(3-5)^2}\) \(=\sqrt{1+4}\) \(=\sqrt{5}\) units \(BC=\sqrt{(-2-2)^2+(-1-3)^2}\) \(=\sqrt{16+16}\) \(=4\sqrt{2}\) units \(AC=\sqrt{(-2-1)^2+(-1-5)^2}\) \(=\sqrt{9+36}\) \(=3\sqrt{5}\) units \(\because\sqrt5<\sqrt{32}<\sqrt{45}\) \(\Rightarrow AB<BC<AC\) But AB+BC \(=\sqrt5+4\sqrt2\) \(=2.236+5.657\) \(=7.893\neq6.708\) i.e., AB+BC \(\neq\) AC \(\therefore\) Points A, B and C are not collinear. Also, they are not vertices of isosceles & right angled triangle. Hence, given points A, B and C are non-collinear. Correct option is D) non-collinear |
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