If 50% is 15 what is 75%

In the diagram, gef and hef are congruent. what is the value of x

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)

Maren is buying carpet for her rectangular living room. the room is 4.8 yards wide and 5.2 yards long. how much carpet does she need to buy? enter your answer as a decimal in the box. yd2