Approximately 7.4 inches. You can use the Pythagorean theorem to get you diagonal or hypotenuse.
By the law of cosines, the angle

satisfies

which reduces to

which converts to approximately 77 degrees (this can be done my multiplying by 180 and dividing by pi).
Answer:
The probability is 
Step-by-step explanation:
If she has n distinct password candidates and only one of which will successfully log her into a secure system, the probability that her first first successful login will be on her k-th try is:
If k=1

Because, in her first try she has n possibles options and just one give her a successful login.
If k=2

Because, in her first try she has n possibles options and n-1 that are not correct, then, she has n-1 possibles options and 1 of that give her a successful login.
If k=3

Because, in her first try she has n possibles options and n-1 that are not correct, then, she has n-1 possibles options and n-2 that are not correct and after that, she has n-2 possibles options and 1 give her a successful login.
Finally, no matter what is the value of k, the probability that her first successful login will be (exactly) on her k-th try is 1/n
Numerator divided by denominator turns it into a fraction
Answer:
(-6,-4)
Step-by-step explanation:
A reflection over the x-axis changes the y variable
(x,y)--->(x,-y)