The area of a parallelogram is base multiplied by height and therefore 18/2 and there you go.
Solution:
We have been asked to find the distance between the points (3, 3) and (7, 3).
we can find the distance between the two points using the distance formula.
The distance formula is given as

Now substitute the given values we get

Hence the distance between the given points is 4
The diameter fits all the way across the circle, and the radius fits half way across the circle, thus making the radius half the length of the diameter so the ratio for diameter/radius would be 2/1 or 1/.5
I think the answer is C.
Good luck!