#(/_A,/_B,/_C) = (25^@,78^@,77^@)# #(a,b,c)=(13.7,31.71,31.59)# #color(white)("XXX")#(#b# and #c# are approximate)
Explanation:
If #/_A=25^@#
and #/_B=78^@#
then #color(white)("XXX")/_C=180^@-(25^@+78^@)=77^@#
Given #a=13.7# and using the Law of Sines #color(white)("XXX")b=a/(sin(/_A))*sin(/_B) ~~31.7085733#
and #color(white)("XXX")c=a/(sin(/_A)) * sin(/_C) ~~31.58611706#