STEP 1: find diagonal $ d1 $
To find diagonal $ d1 $ use formula:
$$ \sin \left( \frac{ \alpha }{ 2 } \right) = \dfrac{ d_2 }{ d_1 } $$After substituting $ \alpha = 26^o $ and $ d_2 = \frac{ 64 }{ 5 } $ we have:
$$ \sin \left( \frac{ 52^o }{ 2 } \right) = \dfrac{ d_2 }{ } $$ $$ \sin( 26^o ) = \dfrac{ \frac{ 64 }{ 5 } }{ d_1 } $$ $$ 0.4384 = \dfrac{ \frac{ 64 }{ 5 } }{ d_1 } $$ $$ d_1 = \dfrac{ \frac{ 64 }{ 5 } }{ 0.4384 } $$ $$ d_1 = 29.199 $$STEP 2: find area $ A $
To find area $ A $ use formula:
$$ A = \dfrac{ d_1 \cdot d_2 }{ 2 } $$After substituting $ d_1 = 29.199 $ and $ d_2 = \frac{ 64 }{ 5 } $ we have:
$$ A = \dfrac{ 29.199 \cdot \frac{ 64 }{ 5 } }{ 2 }$$$$ A = \dfrac{ 373.7472 }{ 2 } $$$$ A = 186.8736 $$