To find height $ h $ use formula:
$$ \sin \left( \alpha \right) = \dfrac{ h }{ a } $$After substituting $ \alpha = \frac{ 25 }{ 2 }^o $ and $ a = 4050 $ we have:
$$ \sin( \frac{ 25 }{ 2 }^o ) = \dfrac{ h }{ 4050 } $$ $$ 0.2164 = \dfrac{ h }{ 4050 } $$$$ h = 0.2164 \cdot 4050 $$$$ h = 876.5804 $$