Martin wants to use coordinate geometry to prove that the opposite sides of a rectangle are congruent. He places parallelogram [tex]$A B C D$[/tex] in the coordinate plane so that [tex]$A$[/tex] is [tex]$(0,0)$[/tex], [tex]$B$[/tex] is [tex]$(a, 0)$[/tex], [tex]$C$[/tex] is [tex]$(a, b)$[/tex], and [tex]$D$[/tex] is [tex]$(0, b)$[/tex].

What formula can he use to determine the distance from point [tex]$D$[/tex] to point [tex]$A$[/tex]?

A. [tex]$(0-0)^2+(b-0)^2=b^2$[/tex]

B. [tex]$\sqrt{(a-a)^2+(b-0)^2}=\sqrt{b^2}=b$[/tex]

C. [tex]$(a-a)^2+(b-0)^2=b^2$[/tex]

D. [tex]$\sqrt{(0-0)^2+(b-0)^2}=\sqrt{b^2}=b$[/tex]



Answer :

To determine the distance from point [tex]\(D\)[/tex] [tex]\((0, b)\)[/tex] to point [tex]\(A\)[/tex] [tex]\((0, 0)\)[/tex] in the coordinate plane, we can use the distance formula, which is given by:

[tex]\[ \text{Distance} = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \][/tex]

For points [tex]\(A\)[/tex] [tex]\((0, 0)\)[/tex] and [tex]\(D\)[/tex] [tex]\((0, b)\)[/tex]:
- [tex]\(x_1 = 0\)[/tex], [tex]\(y_1 = 0\)[/tex]
- [tex]\(x_2 = 0\)[/tex], [tex]\(y_2 = b\)[/tex]

Plugging the coordinates into the distance formula:

[tex]\[ \text{Distance} = \sqrt{(0 - 0)^2 + (b - 0)^2} \][/tex]

Simplify the expression inside the square root:

[tex]\[ \text{Distance} = \sqrt{0 + b^2} \][/tex]
[tex]\[ \text{Distance} = \sqrt{b^2} \][/tex]
[tex]\[ \text{Distance} = b \][/tex]

Therefore, the correct formula to determine the distance from point [tex]\(D\)[/tex] to point [tex]\(A\)[/tex] is:

[tex]\[ \text{Distance} = \sqrt{(0-0)^2+(b-0)^2} = \sqrt{b^2} = b \][/tex]

Thus, the correct choice is:

D. [tex]\(\sqrt{(0-0)^2+(b-0)^2}=\sqrt{b^2}=b\)[/tex]