Question about the project

Dear Ms. Saatkamp,
I'm just writing to ask about the mathmatician I picked. I'm not really sure if you'll even check the blog anymore, but if you do it would help to know for sure.
The mathmatician i picked wasnt really a mathmatician, who worked in the navy, but he invented the sextant, which is a navigational tool. This tool uses angles from the stars to the horizon to fid your exact place on the map. Is this a geomety discovery? I think it is, because its using geaometry in real life. But I'm not sure if you want more like theorems or things you find in math books. His name in John Campbell, the inventor of the sextant. If you get this can you reply to me and tell me if this discoverer is good? Thank you,
Jenni