Need ! prove that opposite sides of a parallelogram are congruent. using a two column proof

Proof

Step-by-step explanation: First, draw an auxiliary line from one angle to the angle opposite of it.  (Make a diagonal of the parallelogram) Afterwards, the parallelogram will be split into two triangles. You can prove those 2 triangles congruent using alternate interior angles and then the ASA Postulate. After that because corresponding parts of congruent triangles are congruent, you know that A parallelogram's opposite sides are congruent. Hope that makes sense. All you'll have to do is put that into 2 column form

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3

b). 4320 have a nice day