What is tan?need help badly geometry test

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?

Given a normal distribution with µ=20 and σ = 4, what is the probability that x> 24 x< 24 x< 24 or x> 24

Consider kite fghj. what are the values of a and b? a = 14, b = 6 a = 14, b = 8 a = 17, b = 6 a = 17, b = 8