The length of the unknown side of the triangle is 6
The image that completes the question is added as an attachment.
From the attached image, we have the following equivalent ratios:
x : 3 = 8 : 4 = 10 : 5
Rewrite as:
x : 3 = 8 : 4
Express as fraction
x/3 = 8/4
Multiply both sides by 3
x = 6
Hence, the length of the unknown side of the triangle is 6
Read more about similar triangles at:
https://brainly.com/question/14285697
#SPJ1