In this model, 1, -1. i. -i are called four basic colors, white, black, red, green, respectively. A complex number describe a segment with a length and color. Two segment z1and z2 can formed a rectangle with area z1* z2. Therefore we can show the formula (a+b)^2 when they are even negative and imaginary numbers. We can demonstrate quadratic formula when the roots are complex. DIY chance.
