中三三角形的應用

let x be the height of the lamp
sin26=(25-x)/y
sin33=25/y
sin26/sin33=(25-x)/25
0.44/0.54=1-x/25
44/54==1-x/25
x/25=1-44/54
x/25=10/54
x=10x25/54
=4.63m

Let x be the distance between 燈柱 and 建築物
tan(90-33)=x/25
x=25tan57
Let y be the difference of height between 燈柱 and 建築物
tan(90-25)=x/y
y=25tan57/(tan65)
結論:燈柱高度=25m-y=7.05m( 3 sign.)