Type of equations, separated by degree:

Equation of first degree, linear equation:

kx + d = 0

Equation of second degree, quadratic equation:

ax2 + bx + c = 0

Equation of 3rd degree, cubic equation:

ax3 + bx2 + cx + d = 0

When applied it gives a scheme to correctly calculate a figure in a coordinate system.

As correctly pointed out by BrianShader, the list goes on forever. After the cubic equation there is the quartic equation, then there comes the quintic...