Задача:
https://qa.studwork.ru/geometriya/922804-1-tochki-a-i-b-simmetrichny-otnositelno-tochki-c-naydite-koordinaty-tochki-b-esli-a-3-5-7-i-s-6-2-1-2-dany?_ga=2.38417834.809555826.1636533434-793482486.1635849575