look at that image and tell me if you can explain it
i for the life of me can’t
link Pictures
[Edited by bibliophage on 08-29-2001 at 05:46 PM]
James Randi had an explaination on his website about a month ago, but I’m too lazy to go find it. Basically, the slope of the green and red trianges is different. The red is like 5:2 while the green is 8:3. Therefore, there’s a hump or depression in the big “triangle” that affects it’s area, depending on how it’s set up. Essentially, the original shape is a quadrilateral, but it’s very difficult for you to detect.
Thanks for your help
The key is that the “hypoteneus” of the large “triangle” isn’t actually straight. The slant of the dark red triangle isn’t the same as the slant of the dark green triangle, though the difference is so slight that it’s imperceptible to the eye.
An oldy, but a goody. Take a very close look at the junction of the hypotenuses of the red & green triangles, or consider the shape of the two triangles - one has sides of length 2 and 5, the other has sides of length 3 and 8.
In other words, the “hypotenuse” of the large composite triangle isn’t really a straight line. If you can’t see that by looking closely at it, line a piece of paper up against the hypotenuse of one of the triangles.
Simple bonus question, from high school;
Assuming the grid is 1", how much larger is the 2nd triangle than the first?
A lot of the geometry whizkids had trouble with the formula.
Personal to the OP;
I knew I guy named Ted in the 70’s who’s hobby was lapidary. The name painted on the back of his old Power Wagon? “Rocks Teddy”
And welcome to the SDMB. 
Peace,
mangeorge