Find two numbers if their sum is 6.1 and their difference is 1.6

Asailor is looking at a kite. if he is looking at the kite at an angle of elevation of 36and the distance from the boat to the point where the kite is directly overhead is 40 feet, how high is the kite?

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'