Both Rhianna and Christopher were correct as they took different reference angles.
Step-by-step explanation:
Step 1:

The value of the tan of a reference angle is calculated using the above formula.
The hypotenuse is the longest side of the triangle is always opposite the right angle of the triangle.
In this triangle, the hypotenuse is the side measuring 5 units.
Step 2:
When the reference angle is A, the opposite side measures 3 units and the adjacent side measures 4 units.
So 
When the reference angle is C, the opposite side measures 4 units and the adjacent side measures 3 units.
So 
So both Rhianna and Christopher were right as they took different reference angles i.e. A and C.
Answer:
8
Step-by-step explanation:
Answer: 5
This is because (4r + 6) means you take r and multiply that number by 4.
Because there is no number, r would equal one in this case.
4 • 1 is 4
4 + 6 is 10
This would give us 1/2(10)
Half of 10 is 5.
Therefore, the answer is 5.
9514 1404 393
Answer:
(d) 36 feet
Step-by-step explanation:
Use your sense of geometry.
The hypotenuse of a right triangle will never be less than the longest side, and will never be greater than 1.5 times the longest side*.
That means the only reasonable answer choices will be between 30 and 45 feet. There is only one such choice.
The measure is about 36 feet.
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If you like, you can find a more exact value using the Pythagorean theorem. The distance d of interest is ...
d^2 = 20^2 +30^2 = 1300
d = √1300 = 10√13 ≈ 36.0555 ≈ 36 . . . feet
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* The longest hypotenuse will be √2 ≈ 1.4142 times the longest right triangle leg when the two legs are equal length.