In triangles △XYZ and △PQR, ∠Y=60∘, ∠Z=80∘, ∠Q=60∘, and ∠R=80∘. Which additional piece of information is sufficient to prove that △XYZ≅△PQR?
The measure of angle X
The length of side XY
The lengths of sides YZ and QR
The perimeter of △XYZ
