Question

Which statement explains the relationship of sides BA and B'A' after rectangle BADC has been rotated 90° clockwise about the origin?
coordinate plane with rectangle ABCD at A (3,5), B (1,3), C (5,-1), and D (7,1)


Side B'A' has a slope of −1 and is perpendicular to side BA.

Side B'A' has a slope of 1 and is parallel to side BA.

Side B'A' has a slope of 1 and is perpendicular to side BA.

Side B'A' has a slope of −1 and is parallel to side BA.

Answer 1

Answer:

Numbering the options, we have;

1) Side B'A' has a slope of −1 and is perpendicular to side BA.

2) Side B'A' has a slope of 1 and is parallel to side BA.

3) Side B'A' has a slope of 1 and is perpendicular to side BA.

4) Side B'A' has a slope of −1 and is parallel to side BA.

The correct option is;

1) Side B'A' has a slope of -1 and is perpendicular to side BA

Step-by-step explanation:

The given coordinates are;

A(3, 5) B(1, 3), C(5, -1) and D(7, 1)

The slope of BA is found as follows;

$Slope \, of BA= \dfrac{y_{2}-y_{1}}{x_{2}-x_{1}} =\dfrac{3-5}{1-3}= \dfrac{-2}{-2} = 1$

Rotation of a line through 90 degrees gives

(x, y) will be (y, -x)

Therefore, the coordinates of A' = (5, -3)

The coordinates of B' = (3, -1)

Then the slope is given as follows;

$Slope \, of \, B'A' =\dfrac{-1 -(-3)}{3-5}= \dfrac{2}{-2} = -1$

Therefore side B'A' has a slope of -1 and is perpendicular to side BA.