In right pyramid PABCD, ABCD is a square with sides of length 2 and the distance from P to the center of square ABCD is 1. A plane intersects the pyramid at A and intersects edges PB, PC and PD at points B', C' and D', respectively. If and , what is the value of the ratio ? Express your answer as a common fraction.
and 
, what is the value of the ratio 
? Express your answer as a common fraction.