Quote:
Originally Posted by GreenLantern
Found this on that website... is there something obvious I am missing here? |
The upwards slope on the red triangle and the green triangle are not the same - the red triangle goes up 3 units for 8 units of length (37.5%) while the green triangle goes up 2 units for 5 units of length (40%). So the first example is slightly bowed downward, while the second is slightly bowed upward, making room for the empty square.
red triangle = 12 squares area
green triangle = 5 squares area
yellow boxes = 7 squares area
green boxes = 8 squares area
total - 32 squares area
The first aggregrate "triangle" LOOKS like is 32.5 squares big (13X5 divided in half), but is actually 32 squares big (add up the smaller shapes) - angled inwards. The second triangle LOOKS like it is 32.5 squares big and missing a piece (bringing it down to an apparent 31.5), but the angle would actually make it 33 squares big (angled outwards), which is why when you "remove" the square you still have the original 32 squares you started with.