Please help it’s for a test

The sixth grade art students are making a mosaic using tiles in the shape of right triangles.each tile has leg measures of 3 centimeters and 5 centimeters.i f there are 200 tiles in the mosaic what is the area of the mosaic.

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.

What describes horizontal cross section of the right rectangle 6m 8m 5m