All of the triangular faces of a pyramid intersect at the

Can someone answer these problems for me

1. are the triangles similar and if so why? what is the value of x? show your work.

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.