Answer:
6 feet
Step-by-step explanation:
cos = adj/hyp
cos76 = adj/24
multiply both sides by 24
24 * cos76 = adj
5.806125494392025 = adj
Rounded
6 feet
There are two so I'll give you the answer to both! 4,000 and 400
Consider that the initial length and width of the rectangle are given as,

After the length is increased by 10%, the new length (L) of the rectangle is calculated as,

After the width is decreased by 10%, the new width (B) of the rectangle is calculated as,

Then the area (A) of the new rectangle is calculated as,

Thus, the new area of the rectangle is 396 square meters.
You're assuming that this data set represents all of Mrs. Hassaan's pupils. Certain students could be missing from the histogram - for instance, there could be one or two students who missed the test, but for certain reasons will be taking a make-up exam. Their grade would not be recording in this data set, but they still contribute to the class size, and so would be unaccounted for here.