How do you find the distance between (–3, –2) and (1, 4)?

1 Answer
Jul 1, 2015

D = 2.sqrt(13)

Explanation:

The distance between two points A(x;y) and B(x';y') can be calculate with the formula :

D = sqrt((x'-x)^2+(y'-y)^2)

Then for : A(-3;-2) and B(1;4) we have :

D = sqrt((1-(-3))^2+(4-(-2))^2)

D= sqrt(4^2 + 6^2)

D = sqrt(16+36) = sqrt(52) = 2.sqrt(13)

The distance between A(-3;-2) and B(1;4) is exactly 2.sqrt(13)

Why this formula work ? In fact, we only calculate the length of vector(BA), and we implicitly use the Pythagorean theorem on it.