Question

Plot and connect the points A (4, 2), B (-3, 2), C(-3, 5), D (4, 5), and find the length of AB.

Answer 1

Answer:

AB = 7

Step-by-step explanation:

The y-coordinate of point A and B is the same.

Therefore, both points lie on the same horizontal line (y = 2).

So determine the distance between them, subtract the x-coordinate of B from the x-coordinate of A:

AB = 4 - -3 = 4 + 3 = 7

However, to calculate the distance between 2 points, regardless if the points are on a horizontal (or vertical) line, you can always use the distance between 2 points formula that is derived from Pythagoras' Theorem, as follows:

let $(x_1,y_1)$ = point A (4, 2)

let $(x_2,y_2)$ = point B (-3, 2)

using the distance between two points equation:

$AB=\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}$

$\implies AB=\sqrt{(-3-4)^2+(2-2)^2}$

$\implies AB=\sqrt{(-7)^2+(0)^2}$

$\implies AB=\sqrt{49}$

$\implies AB=7$

*Edited to add a plot diagram*