What happens to the leg muscle of an athlete who runs a marathon race?

The hip flexors and extends work with the quad area and the hamstring to move the leg muscles forward and backward. the hip rotator muscle stabilize the hip joints.
the link below explains in more detail about the leg muscles used in running.

https://adventure.howstuffworks.com/outdoor-activities/running/training/leg-workouts-for-runners1.htm

First set are parallel, second are perpendicular, third are perpendicular, fourth are neither.

*If you can't remember the rules, or want to check your answers, I would type them into a graphing calculator. It will easily tell you which category they're in. (desmos.com)*

Step-by-step explanation:

1. Same slope (6/5) = parallel

2. Reciprocal (flipped) slope, opposite signs

3. Reciprocal (flipped) slope, opposite signs

4. Neither, the slopes aren't the same or flipped

When you flip the slopes (3/4 becomes 4/3) and change a sign, the lines will always be perpendicular.

Hope it helps :)