Answer: Science test ; he found planets had elliptical orbits, Kepler ; he performed a systematic mapping of sky, Brahe ; uses a large glass lens, refracting telescope.
The lines that tell you the legs are the same length let you know that angle a and angle acb are the same. so 180 -30 is 150 divided by 2 is 75 so c is 75. then take 180 -75 and you get x.
