What states a rule using variables.

A Formula

Step-by-step explanation:

Formulas represent a synthesis of the development of reasoning and are made up of numbers and letters that represent the variables. Knowing them is necessary to solve many problems that are charged in tests and college entrance exams, especially by reducing the time to resolve an issue often. In short, we can say that a formula is what states a rule using variables.

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.

fyuh

step-by-step explanation:

gvfvhv