I need to create an equation/call up a formula, but im not sure which one

So my inital problem is that I need to use an array of tables which imported into matlab, however I need to use the length and the height of a ramp to determine the angle measurement of the ramp, and by doing this i need to create a funcution that accepts the Height and length as inputs and outputs the results. If anyone could help guide me through this, please feel fre to answer.

image provided to better understand the problem:

the parts scribled out is the parts ive already completed. I dont realy need so much help on 5-6 but i do need help on 3 through 4.