Question

could some one please help me find the value of E

Answer 1

You can use the Law of sines:

$\cfrac{p}{sin40^o}= \cfrac{e}{sin55^o} \ \ \ \to \ \ \ e= \cfrac{p*sin55^o}{sin40^o} =\cfrac{12*0.819}{0.643} \approx 15.3 \ units$