Hier die Skizze
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tan ( 28.5 ) = h / ( 4 + y )
tan ( 39 ) = h / y
0.543 = h / (4 + y )
0.81 = h / y
4 * 0.543 + 0.543 * y = h
0.81 * y = h
4 * 0.543 + 0.543 * y = 0.81 * y
2.172 = 0.81 * y - 0.543 * y
0.267 * y = 2.172
y = 8.13 m
Höhe :
tan ( 39 ) = h / 8.13
h = 0.81 * 8.13 = 0.81 * 8.13
h = 6.59 m
Bitte nachrechnen.