Final answer:
The length of the slide is 3 meters.
Step-by-step explanation:
To find the length of the slide, we need to add the distance Maria walks to get from the end of the slide back to the ladder and the distance she climbs to the top of the slide again.
We are given that she walks 1 meter and climbs 2 meters.
Therefore, the length of the slide is:
1 meter + 2 meters
= 3 meters.