geomtrical algorathim

What is a necessary condition for placing rectangle R1 inside of rectangle R2?
What is a sufficient condition for placing rectangle R1 inside of rectangle R2?
Can you fit rectangle R3 inside of rectangle R2, and why
R1= 1.5 X 0.6
R2= 1.8 X 0.9
R3= 2.0 X 0.4