The graph can be divided into two shapes. A rectangle and a right triangle.
The distance that the rover will cover if it completes one circuit can be computed using the Pythagorean theorem and adding the sides of the rectangle.
This is the concept of arithmetic, if you increase your score of 85% by 7%, you will have a score of: New score=old score+increase =85+7 =92% the new score will be 92%