9514 1404 393
Answer:
x = 4
Step-by-step explanation:
Corresponding segments of similar triangles are proportional. Here, the similar triangles are ...
ΔABC ~ ΔADE
so the relationship between the sides is ...
BC/BA = DE/DA . . . . . . we put the unknown value in the numerator
x/4 = 12/(4+8)
x = 4(1) = 4
The length of side x is 4.