Answer:
[tex]4\sqrt{5}[/tex]
Step-by-step explanation:
Since these two triangles are similar by AA, the ratio of their corresponding sides must be the same. In other words:
[tex]\dfrac{4}{z}=\dfrac{z}{20}[/tex]
Cross multiply:
[tex]z^2=80[/tex]
Take the square root of both sides:
[tex]z=\sqrt{80}=4\sqrt{5}[/tex]
Hope this helps!
