Step-by-step explanation:
Given
Two similar triangles i.e. [tex]\trianle ABC \ \text{and}\ \triangle A'B'C'[/tex]
from the figure, In [tex]\triangle ABC[/tex]
[tex]\Rightarrow \cos \alpha=\dfrac{AC}{AB}=\dfrac{3}{5}[/tex]
Also, In [tex]\triangle A'B'C'[/tex]
[tex]\Rightarrow \cos \alpha =\dfrac{A'C'}{A'B'}=\dfrac{6}{10}=\dfrac{3}{5}[/tex]
