10.8 split amongst 18

Marie drew the triangle shown. she wants to draw a second triangle that is different from this one. use the drop-down menus below to complete the statements about the second triangle.

There were 816 people at a concert when a band started to play. after each song, only half the people stayed to hear the next song. how many people were left at the concert after x songs? write a function to represent this scenario.

The triangles are similar. what is the value of x? show your work.