SOLUTION
Step1; Draw the Triangle and locate the angles
We are to obtain the value of a that is the side |BC|
Applying trigonometry ratios we have
[tex]\begin{gathered} \text{hypotenuse}=c=31 \\ \text{Adjacent}=a \\ \theta=57^0 \end{gathered}[/tex][tex]\begin{gathered} \cos \theta=\frac{adjacent}{Hypotenuse} \\ \cos 57^0=\frac{a}{31}\ldots.\text{ cross multiply} \\ a=31\times cos57^0 \end{gathered}[/tex][tex]\begin{gathered} a=31\times0.8999 \\ a=27.89 \end{gathered}[/tex]
Then the value of a = 28mm to the nearest whole number
