I’m confused and I need help with this question?

Sketch one cycle if the cosine function y=2cos2theta

Is the square root of 4 plus the square root of 16 rational?

Koji is installing a rectangular window in an office building. the window is 823 feet wide and 534 feet high. the formula for the area of a rectangle is a=bh. what is the area of the window? enter your answer as a mixed number in simplest form in the box. $$ ft2