Answer:

Explanation:
Pythagorean theorems can be applied to solve this problem.
Pythagorean theorem:

⇒ c²-b²=a²
8²-6²=28²
Solve.
PEMDAS stands for:
- Parenthesis
- Exponents
- Multiply
- Divide
- Add
- Subtract

Solve by exponents from left to right numbers.


Then, subtract.

a=√28
Therefore, the correct answer is a=√28.
I hope this helps you! Let me know if my answer is wrong or not.