in triangle ABC shown, DE || AC. What is the length of AC?

Answer:
AC = 20
Step-by-step explanation:
Δ BDE and Δ BAC are similar, so the ratios of corresponding sides are equal, that is
[tex]\frac{AC}{DE}[/tex] = [tex]\frac{BA}{BD}[/tex] , substitute values
[tex]\frac{AC}{8}[/tex] = [tex]\frac{10}{4}[/tex] ( cross- multiply )
4AC = 80 ( divide both sides by 4 )
AC = 20