Answer:
The name of the long valley that extends along the 'eastern side of Africa' and has several long slender lakes on its floor is the 'Great Rift Valley'.
Step-by-step explanation:
- The 'Great Rift Valley' is an approximately 6000 kilometers long valley that is formed due to the orientation of a number of vertical trenches right from the western Asian country of Lebanon to the southeastern African country of Mozambique.
- The width of the valley varies tremendously all throughout its course.