STEP 1: find angle $ \alpha $
To find angle $ \alpha $ use formula:
$$ \sin \left( \frac{ \alpha }{ 2 } \right) = \dfrac{ d_2 }{ d_1 } $$After substituting $d_2 = 14.9\, \text{cm}$ and $d_1 = 25.6\, \text{cm}$ we have:
$$ \sin \left( \frac{ \alpha }{ 2 } \right) = \dfrac{ 14.9\, \text{cm} }{ 25.6\, \text{cm} } $$ $$ \sin \left( \frac{ \alpha }{ 2 } \right) = 0.582 $$ $$ \frac{ \alpha }{ 2 } = \arcsin\left( 0.582 \right) $$ $$ \frac{ \alpha }{ 2 } = 35.5935^o $$$$ \alpha = 35.5935^o \cdot 2 $$$$ \alpha = 71.1871^o $$STEP 2: find height $ h $
To find height $ h $ use formula:
$$ \sin \left( \frac{ \alpha }{ 2 } \right) = \dfrac{ h }{ d_1 } $$After substituting $\alpha = 71.1871^o$ and $d_1 = 25.6\, \text{cm}$ we have:
$$ \sin \left( \frac{ 71.1871^o }{ 2 } \right) = \dfrac{ h }{ d_1 } $$ $$ \sin( 35.5935 ) = \dfrac{ h }{ 25.6 } $$ $$ 0.582 = \dfrac{ h }{ 25.6 } $$$$ h = 0.582 \cdot 25.6 $$$$ h = 14.9 $$