A picture window has dimensions of 1.40 m X 2.50 m and is made of glass 5.20

Question:

A picture window has dimensions of 1.40 m X 2.50 m and is made of glass 5.20 mm thick. On a winter day, the outside temperature is -20.0°C, while the inside temperature is a comfortable 19.5°C.
(a) At what rate is heat being lost through the window by conduction?
(b) At what rate would heat be lost through the window if you covered it with a 0.750-mm-thick layer of paper (thermal conductivity 0.0500)?