Answer:
6.4 inches
Explanation:
See figure attached.
The perimeter of a triangle is obtained adding the length of all its sides. If the two triangles are congruent, then, all of they sides and angles are equal. Therefore QR = XY = 1.4 inches and PQ = PR = XZ = YZ = 2.5 inches. So, perimeter = QR + PQ + PR = 1.4 + 2.5 + 2.5 = 6.4 inches.