Question

ABCD is a square If angle PQR is equal to 90°PB=QC=DR prove that angle QPR =45°

Answer 1

PBCR is a rectangle 
PB=RC= z
⇒AP=z
If QC=RC=z        
 ∴∠CRQ=∠RCQ= 45 degree
 ∠PRC= 90 degree
∴∠PRQ= 45 degree
sum of angles of a triangle = 180 degree
∴∠PQR=  and ∠PRQ= 45 degree
∴∠QPR=180-(90 + 45)= 45 degree