1) The speed of light is approximately 299,792,458 meters per second.

2) The Nile River, spanning approximately 6,650 kilometers (4,130 miles), is the longest river in the world. It flows through eleven countries in northeastern Africa, supporting various civilizations throughout history and serving as a vital source of water and transportation.

3) The concept of compound interest can be attributed to the ancient Babylonians, who used it in their banking practices.

4) The word "triangle" contains four vowels: I, A, E, and E.