Draw a line $p$ parallel to a line $q$ and passing through the point $P$ ($P$ should not lie on line $q$).

Is this triangle can be constructed and why?

$△PQR: \angle P=120°, \angle Q=70°, PQ=6 \mathrm{cm}$

Is this triangle can be constructed and why?

$△ABC: \angle A=60°, \angle B=60°, \angle C=60°$

Is this triangle can be constructed and why?

$△XYZ: \angle Z=90°, \angle Y=90°, XY=7 \mathrm{cm}$