Line segment PQ is reflected across two lines as described below.
• WhenPQ¯¯¯¯¯is reflected over line a, the image ofP (7,−6) is P′ (5,−1).
• WhenP′Q′¯¯¯¯¯¯¯is reflected over line b, the image ofP′ (5, 1) is P'' (1, 9).
Which of the following is not true?
Lines a and b are parallel.
PQ, P′Q′, and P′′Q′′ are congruent.
The midpoint of P′P′′ lies on line b.
Points Q, Q′, and Q′′ form a scalene triangle.