This is about similar polygons in geometry

Answer:
Father's shadow is 9 feet long.
Step-by-step explanation:
From the given figure,
ΔABC and PQR will be similar.
So their corresponding sides will be proportional.
[tex]\frac{AC}{PR}=\frac{BC}{QR}[/tex]
[tex]\frac{AC}{7.5}=\frac{6}{5}[/tex]
AC = [tex]\frac{6\times 7.5}{5}[/tex]
AC = 9 feet
Therefore, measure of the father's shadow is 9 feet.