We will prove first that PRQ≡PSQ We need 3 attributes from the each triangle: QS=QR PR=PS PQ=PQ
from PRQ≡PSQ => angles RPQ and SPQ are equal
Let if be O=RS∩PQ
We will prove that triangles RPO≡SPO We need 3 attributes from the each triangle: RP=PS PO=PO angles RPQ and SPQ are equal
results that angles RPO and SPO are equal(Let's note them with x) We also know that (as angles) POS≡ROS and POR≡SOQ as opposite angles
We now have than 4x=360 wich means x=90. And we proved the desired result. You just need to put this explanation into the table. (most if the 3 attributes for each triangle)
