The answer is 6c=2.75 hope this helps
You need to a table of the standard normal cumulative distribution
Here is one:
https://math.ucalgary.ca/files/math/normal_cdf.pdf
the closest value I see is 0.85
as you already know, the area of a rectangle is just length*width, so is just the product of those two.

The answer is 106 your welcome :-)