Final answer:
The solution set for the equation |a| = 6 would be marked at points 6 and -6 on a number line, as these are the two values of 'a' that have an absolute value of 6.
Step-by-step explanation:
The number line that shows the solution set for |a| = 6 would have two points, because the absolute value of 'a' can be either 6 or -6. Both these numbers have an absolute value of 6. So, on the given number line, you would mark the points at 6 and -6 to represent the solution set for the equation |a| = 6.