Press space or use the arrow keys to change slides and enjoy! Have you ever seen a lunar eclipse? Tell me about it in the comments! Note: During the mathematical explanation of how often eclipses occur, some concepts are introduced and not much is said about them. Here are some short explanations. Triangle Sum Theorem: If you have the measures of two angles in a triangle, you can find the third by subtracting those two measures from 180°. Law of Sines: The sine of an angle over the length of its opposite side is equal to the sine of any other angle over the length of its opposite side. Opposite Side: The side of a triangle that is not adjacent to/makes up an angle. Leg: One of the sides of a right triangle that is adjacent to the right angle. Sine: The length of the opposite side divided by the hypotenuse of a right triangle. 6/4/18: Featured?!? Oh my gosh! This is insane! Thanks for all the awesome comments detailing your eclipse experiences! However, I may not be able to respond to all of them, but I'll do my best! Please refrain from advertising here. Any and all advertisement comments will be deleted. Additionally, if you do decide to remix, please remember to change something. Exact copies aren't okay, but if you'd like to make an addition or just play around with the code, go ahead!