Respuesta :

Answer:

x = 10.0

Step-by-step explanation:

Using the geometric mean formula:

       x                projection

-----------------  =  ---------------

entire base              x

Here, the projection is 5 and the entire base is (20 + 5). So:

       x                5

------------  =  ------------

      25              x

Cross multiply:

x² = 25 (5)

x² = 100

√x² = √100

x = 10