(3b + 5x)7 please help

Thales was an ancient philosopher familiar with similar triangles. one story about him says that he found the height of a pyramid by measuring its shadow and his own shadow at the same time. if the person is 5-ft tall, what is the height of the pyramid in the drawing?

Adam used 1072.4 gallons of water over the course of 7 days. how much water did adam use, on average, each day?

Fast! find the length of cu. the triangles are similar. show your work.