A quadrilateral MUST be a parallelogram if it has one pair of opposite sides both parallel and congruent. A quadrilateral MUST be a parallelogram if it has both pairs of its opposite angles congruent (or equal in measure). A quadrilateral MUST be a parallelogram if it has both diagonals bisecting each other.
42 because it is all of the sides have to be added up for the perimeter so the formula would be 14+14+7+7.
Answer:
yes
Step-by-step explanation:
because we are simply "adding" 2 negative numbers.
-8n + -7 = -7 + -8n
as long as we flip the terms around with their signs, the commutative principle of addition applies.
what we CANNOT do is e.g.
8n - 7 = 7 - 8n
THERE would be a problem.
but again, by also keeping the signs with the terms, it is all OK.
so, yes, we could also do
8n - 7 = -7 + 8n
that is true again.
