Question 1134787
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<pre>
Start from  the definition which  <U>EVERYBODY knows</U>  (or must know)


    {{{b/a}}} = tan(B)


and deduce from it   a = {{{b/tan(B)}}}.


After that use your calculator . . . 
</pre>


Do not use the way pointed by @josgarithmetic - otherwise everybody will see that you don't know Trigonometry . . .