Please Help this is Due in 1 hour and I really dont understand any of this. (Question in Image)

Answer:
5.14
Step-by-step explanation:
The way i solved this was i found the length of the line by taking the 2 (Width and also "A") and the 7 (The height and also "B"), squared both of them and added them together. Then found the square root. Sense i suck at explaining things this is what the equation should have looked like. [tex]\sqrt{(2^{2} +7^{2})[/tex] ÷ 2. (Side wait for someone else to answer because i'm 70% sure this is right.