In the diagram, dec is a blank of abc across like k

reflection

step-by-step explanation:

by observation, we can see that if we reflect triangle abc across the line k, we get triangle dec

The average age is 7.1 years.

This problem is an example of when we need to take a weighted average. We simply can't just find the average of 5 and 8, because there are different children of each each.

To start, lets multiply the total number of children by their individual ages.

6 x 5 = 30 years
14 x 8 = 112 years

There are 142 years among the 20 years, so divide 142 by 20. This gives us an average age of 7.1 years.