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:
Step-by-step explanation:
If you call "5x-2x^2+1" an "equation," then you must equate 5x-2x^2+1 to 0:
5x-2x^2+1 = 0
This is a quadratic equation. Rearranging the terms in descending order by powers of x, we get:
-2x^2 + 5x + 1 = 0. Here the coefficients are a = -2, b = 5 and c = 1.
Use the quadratic formula to solve for x:
First find the discriminant, b^2 - 4ac: 25 - 4(-2)(1) = 25 + 8 = 33
Because the discriminant is positive, the roots of this quadratic are real and unequal.
-b ± √(discriminant)
Applying the quadratic formula x = --------------------------------
2a
we get:
-5 ± √33 -5 + √33
x = ----------------- = --------------------- and
2(-2) -4
-5 - √33
---------------
-4
Answer:
y = 5
Step-by-step explanation:
The triangles will be congruent when corresponding sides are congruent. __
We already have ...
KL ≅ NP . . . = 15 mm
JL ≅ MP . . . = 22 mm
So, we need ...
JK ≅ MN
4y +12 = 32 . . . . substitute given values
This will be the case when ...
4y = 20 . . . . . subtract 12
y = 5 . . . . . . . divide by 4
The value of y that makes the triangles congruent is 5.
If you list all the common factors, (1,2,3,6), you see the highest common factor is 6