Question

Riko wants to find the distance between the points (−2, −3) and (2, −5). His work is shown. The distance is 8 units. Riko correct? Explain why or why not.

Answer 1

Answer:Sample Response: No, Riko is not correct. The points do not have the same x-coordinates. If you connect the points, they do not form a horizontal or vertical line, so you cannot count spaces or use absolute value to find the distance.

Explanation:

Answer 2

incorrect

Explanation:

The calculation he has done only calculates the distance between the y- coordinates of the points.

Calculate the distance d using the distance formula.

d = √ (x₂ - x₁ )² + (y₂ - y₁ )²

with (x₁, y₁ ) = (- 2, - 3) and (x₂, y₂ ) = (2, - 5)

d =
`√((2+2)^2+(-5+3)^2)`

=
`√(4^2+(-2)^2)`

=
`√(16+4)`

=
`√(20)` =
`√(4(5))` = 2
`√(5)` ← exact distance