tan 29 = o/x o= opposite the height of the mesa (less stephan's 1.8 ht)
tan 25 = o/(100+x) solve both of these equations for 'o' and set them equal to each other
(100+x) tan 25 = x tan 29 solve for x = 529.87 m from the mesa
so now we know
tan 29 = o/529.87 o = 293.71....
add Stephan's height 1.8 + 293.71 m = 295.51 m = height of mesa
BUT..... don't forget to add the 1.8m height of Stephan once you find your answer !!