MathDB

Triangle

ABC

lies in the first quadrant. Points

A

B

, and

C

are reflected across the line

y=x

to points

A'

B'

, and

C'

, respectively. Assume that none of the vertices of the triangle lie on the line

y=x

. Which of the following statements is not always true?

(A)

Triangle

A'B'C'

lies in the first quadrant.

(B)

Triangles

ABC

and

A'B'C'

have the same area.

(C)

The slope of line

AA'

-1

(D)

The slopes of lines

AA'

and

CC'

are the same.

(E)

Lines

AB

and

A'B'

are perpendicular to each other.

Problem Statement