Answers:
B = 50
a = 10.9
c = 17.0
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Step-by-step explanation:
This is a right triangle, so the acute angles are complementary, meaning they add to 90
B+40 = 90
B+40-40 = 90-40
B = 50
Also, because this is a right triangle, we can use trig ratios to compute the missing sides
tan(angle) = opposite/adjacent
tan(40) = a/13
a = 13*tan(40)
a = 10.908
a = 10.9
cos(angle) = adjacent/hypotenuse
cos(40) = 13/c
c*cos(40) = 13
c = 13/cos(40)
c = 17.0
note: make sure your calculator is in degree mode