Final answer:
To find AB in the truss bridge, we can use the fact that triangles ABC and XYZ are similar and set up a proportion.
Step-by-step explanation:
In order to find the length of AB, we need to use the given information that triangles ABC and XYZ are similar.
Since triangles are similar, their corresponding sides are proportional.
Therefore, we can set up the following proportion:
AB/XY = BC/YZ
Substituting the given values, we have:
AB/20 = 7/28
Cross multiplying and solving for AB, we get:
AB = (20 * 7) / 28 = 5
Therefore, the length of AB is 5 meters.