Question

Using distance formula, show that the points (-3, 2), (1, -2) and (9, -10) are collinear.

Answer 1

Let the given points (-3, 2), (1, -2) and (9, -10) be denoted by A, B and C, respectively. Points A, B and C will be collinear, if the sum of the lengths of two line-segments is equal to the third.

Since, AB + BC = 4√2 + 8 2 = 12√2 = AC , the, points A, B and C are collinear.