Question

PQ = |9 - (-3)| = 12
QR = |-2 - (7)| = -9
PR = sqrt(9 - (-3))^2 + (-2 - (7))^2
= sqrt 12^2 + (-9)^2
= sqrt 144 + 81
= sqrt 225
= 15

12 + 15 + (-9) = 18

The perimeter of PQR is 18 units.

Does this problem look correct? Ruler postulates are fun. :D

Answer 1

\[PQ = |9 - (-3)| = 12\]\[QR = |-2 - (7)| = -9\]\[PR = \sqrt(9 - (-3))^2 + (-2 - (7))^2\]\[[\sqrt (12^2) + (-9)^2]\]\[(\sqrt 144 + 81)\]\[\sqrt 225\]\[= 15\]\[12 + 15 + (-9) = 18\]

Answer 2

Something looks wrong here. Does anyone know?