What is a numerators charracteristics??

Jim is painting the inside of a circular helicopter pad. how many cans of paint would he need if the pad is 50 feet across and each can of paint covers about 200 ft2.

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.

See attachment below and find the equivalent of tan(∠qsr)