<human>:  How do I sew a hem on a pair of pants?
<bot>: To sew a hem on a pair of pants, you will need a sewing machine, thread, scissors, and a straight ruler or measuring tape. Begin by turning up the hem at the desired length and pressing it in place. Secure the hem on one side with pins or sewing clips. Then, using a thread that matches the pants, set up your sewing machine and begin stitching along the hem. Be sure to use small, even stitches and keep them close together. Once done, remove the pins and trim any loose threads. Your hem should now be securely in place.