Trigonometry

• Ok, it's not all of trig, but some simple concepts.
• A line is defined by an equation ax+by+c = 0. (You can do it with other equations.)
• It represents an infinite number of points (x,y values) that meet this equation.
• It can also be defined by two separate points.
• A ray is half a line.
• A line seqment is all the points of a line between two selected points.
• There's no need to overthink these things, they're pretty simple.
• Angles are "the measure of divergence of two rays that share the same origin".
• You can measure it in degrees (a circle is 360 degrees).
• A circle also has 2pi radians.
• a^2+b^2=c^2 is the pythagorean theorem for right triangles.
• The size of the hypotenuse (c) has a relation to the other sides of a right triangle.
• So if one side (next to the right angle) is 5 long, and the other 12, how long is the hypotenuse?
• You use this stuff to move around in 2 and 3-D games.