Answer:
17 ft
Step-by-step explanation:
Use pythagorean theorem:

The rectangular storage unit is split into 2 right triangles since it is 17 feet diagonally. So, 17 feet is the hypotenuse of the right triangle.

Once you solve everything you will find that x^2 = 225, so x = 15 ft. That is the length of the storage unit.
A= a^2 = 6^2 = 36
answer <span>D.
36 ft2</span>
The answer is D, Multiplication
N(2n+6)-(n²-1)= 2n²+6n-n²+1=n²+6n+1