To solve for the base length of the triangle, we'll need to use the properties of similar triangles. When two triangles are similar, the corresponding sides are proportional. However, from the question provided, I don't have access to the image showing the triangles, which might help in understanding the exact ratio or proportionality between the sides.

If you can provide more information or upload the image, I can give you a more precise answer!

Alternatively, if the image shows specific dimensions or relationships between the similar triangles, you can share those and I will calculate the base length for you.