I would say that it's an acute angle ....
Answer:
For a function f(x), a vertical stretch of scale factor K is written as:
g(x) = k*f(x)
And for a function f(x), a vertical translation of N units is written as:
g(x) = f(x) + N
If N is positive, the translation is up
if N is negative, the translation is down.
1) We have the function:
y = f(x) = 5^(x - 2)
A vertical stretch of factor 3 will be:
y = g(x) = 3*f(x) = 3*(5)^(x - 2)
2) We have the function:
y = f(x) = 7.2^x
A translation up of 8 units will be written as:
y = g(x) = f(x) + 8 = 7.2^x + 8
All we have to do is subtract 11 - 13 to get our answer.
Answer: A) z = -2.
To find an angle measure, you would do inverse tan.

You may need to hit the second button on your calculator to get this function.
Your answer turns up to be 64.402~~~~.
Rounded, the answer is 64 degrees.
Hope this helps!
:)