This is solving multiple step equations

In triangle abc segment de is parallel to the side ac . (the endpoints of segment de lie on the sides ab and bc respectively). find de, if ac=20cm, ab=17cm, and bd=11.9cm;

Iam stuck on one problem. my mind is in absoloute vacation mode. i literallty just need to finish this to be done will give brainliest and all my points if i have to! 1- point free throw and 2- point feild goal. he made 35 shots, and scored 62 points how many of each shot did he make in 1 minute? (i already did the math. he made 8 1-point free throws and 27 2-point feild goals.) 1. write two equations for the problem. (i had a major brain fart.)

Which one is true about the hexagons ?