Answer:
1. 30°
2.90°
3. 12 units
Explanation:
I can't believe there's nothing confirming that this is a parallelogram/a rhombus?! Assuming is awful, and I wish you could say you can't know for sure lol but for the sake of this answer, let's just call it a rhombus. (There was probably some context elsewhere that you didn't put over here, hopefully.)
1.
The reason I say this is: in a rhombus, the diagonals bisect the angles. This means that the diagonals split the angles they meet into two equal parts. That way, it would make sense. m∠QPR=m∠SPR=30°.
2.
If it is a rhombus, the diagonals are perpendicular to each other, so m∠QTP should be 90°.
3.
Diagnonals in a rhombus (and in any parallelogram) bisect each other, so PT=TR=6, and RP=PT+TR=12 units.
Sorry if this is all dreadfully wrong, and I hope I helped you!