## College Algebra (10th Edition)

$x=40 \\A=50^o \\B=125^o \\C=5^o$
RECALL: Two similar triangles have: (1) corresponding angles that are congruent; and (2) corresponding sides that are proportional Since corresponding angles are congruent, then $A=50^o \\B=125^o \\C=5^o$ Corresponding sides of similar triangles are proportional. Thus, $\dfrac{10}{8}=\dfrac{50}{x}$ Cross-multiply to obtain: $\begin{array}{ccc} &10(x) &= &50(8) \\&10x &= &400 \\&\frac{10x}{10} &= &\frac{400}{10} \\&x &= &40\end{array}$