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.
9 :
Given,
Perimeter = 88 units
Base = x + 4
Height = x - 6
= > Perimeter of Rectangle = 2( base + height )
= > 88 = 2{ ( x + 4 ) + ( x - 6 ) }
= > 88 / 2 = { x + 4 + x - 6 }
= > 44 = 2x - 2
= > 46 = 2x
= > 46 / 2 = x
= > 23 = x
Therefore,
Length of base = ( x + 4 ) units = ( 23 + 4 ) units = 27 units
Length of height = ( x - 6 ) units = ( 23 - 6 ) units = 17 units
10 :
Given,
First integer = x
Second integer = x + 2
Third Integer = x + 4
Given that the sum of all integers is 36
= > ( x ) + ( x + 2 ) + ( x + 4 ) = 36
= > x + x + 2 + x + 4 = 36
= > 3x + 6 = 36
= > 3x = 30
= > ( 3x ) ÷ ( 3 ) = ( 30 ) ÷ ( 3 )
= > x = 10

Value of first integer = x = 10
Answer:
6.25 lb and 100 oz
Step-by-step explanation:
One lb (Pound) is equal to 16 oz (Ounce). Therefore, 100 oz equals...
100 oz / 16 = 6.25 lb
and
100 oz = 100 oz
Answer:
8.6 but im not sure.
Step-by-step explanation:
5 squared + 7 squared = 74 square root = 8.6
Answer:
Minimum
Step-by-step explanation:
A minimum occurs when the line goes from decreasing to increasing