Answer:
Step-by-step explanation:
x is the geometric mean because it is a part of both the small triangle on the left (with base 81) and the whole triangle (with base 225). Setting up the geometric means formula:
[tex]\frac{81}{x}=\frac{x}{225}[/tex] and cross multiply to get
[tex]x^2 =18225[/tex] so
x = [tex]\sqrt{18225}[/tex] and
x = 135
