Question

help please, how do I find the value of x?

Answer 1

looks like similar triangles

Answer 2

logically you know that x has to be bigger than b right?

Answer 3

yes

Answer 4

The two triangles are similar by the AA Postulate. (pair of right angles and pair of vertical angles). The vertices of the triangles were assigned labels.

So, Triangle ABC ~ Triangle EBD.
Corresponding sides of similar triangles are in proportion.

AB/EB = AC/ED
15/x = 9/12
Solve for x ----> @SageWilson

Answer 5

9/12=1/1/3
=15(1/1/3)
=20 ft