Math Forum

Forum Thread: How to Determine if a Line Is Perpendicular.

What are perpendicular lines or what is perpendicular? Well perpendicular are two lines that intersect at 90 degree angles. So let's look at a couple of examples of where we will see those. So we have two lines and they are intersecting at 90 degree angles, and I will label it with a little box that represents 90 degrees, and once we know this is 90 degrees we know the other three are 90 degrees because these are lines and lines have a degree of 180 so that would make all four of these 90 deg...

Forum Thread: How to Multiply Using Lines

I have seen this technique described as "Chinese Multiplication", Japanese Multiplication", Vedic Math Multiplication, and even "Ancient Arabic Multiplication". It is a fun way to multiply numbers using lines. I don't know if you can replace traditional forms of multiplication with this technique, but it does work on all numbers.