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The points A(– 2, 1), B(0, 5), C(– 1, 2) are collinear.

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Question

The points A(– 2, 1), B(0, 5), C(– 1, 2) are collinear.

Options

  • True

  • False

MCQ
True or False
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Solution

This statement is False.

Explanation:

Given points are A(– 2, 1), B(0, 5), C(– 1, 2)

Area of ΔABC = `1/2|(-2, 1, 1),(0, 5, 1),(-1, 2, 1)|`

= `1/2 -2|(5, 1),(2, 1)| -1|(0, 1),(-1, 1)| + 1|(0, 5),(-1, 2)|`

= `1/2 |-2(5 - 2) - 1(0 + 1) + 1(0 + 5)|`

= `1/2 |-2 xx 3 - 1 xx 1 + 1 xx 5|`

= `1/2|-6 - 1 + 5|`

= `1/2|-2|`

= 1 sq.unit

So, the given points are not collinear.

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Chapter 10: Straight Lines - Exercise [Page 183]

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NCERT Exemplar Mathematics Exemplar [English] Class 11
Chapter 10 Straight Lines
Exercise | Q 49 | Page 183

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