Answer:
Side ACwith DF
Step-by-step explanation:
This is a problem of Permutations. We have 3 cases depending on the number of B's. Since no more than three B's can be used we can use either one, two or three B's at a time.
Case 1: Five A's and One B
Total number of letters = 6
Total number of words possible = 
Case 2: Five A's and Two B's
Total number of letters = 7
Total number of words possible = 
Case 3: Five A's and Three B's
Total number of letters = 8
Total number of words possible = 
Total number of possible words will be the sum of all three cases.
Therefore, the total number of words that can be written using exactly five A's and no more than three B's (and no other letters) are 6 + 21 + 56 = 83
By using trigonometric relations, we will see that the angle of elevation must be 55°.
<h3>
How to find the angle of elevation?</h3>
We can see this as a right triangle, where one cathetus measures 1250ft (altitude) and the other cathetus measures 875ft.
The angle of elevation is the angle such that the adjacent cathetus is the one measuring 875ft.
Then we can use the relation:
tan(a) = (opposite cathetus)/(adjacent cathetus)
tan(a) = 1250ft/875ft
To find the angle of elevation, we can use the inverse tangent function:
a = Atan(1250ft/875ft) = 55°
The angle of elevation must be 55 degrees.
If you want to learn more about right triangles:
brainly.com/question/2217700
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