Answer:

Step by step
Remember, a reference angle is a positive acute angle that represents an angle θ of any measurement.
a)
, then its reference angle is 
b)
is in the second cuadrant, then its reference angle is 
c)
, then it is in the first cuadrant and the reference angle is
.
d)
and it is in the third cuadrant, then its reference angle is 
Answer:
No. The answer on the right is positive 16 while the answer on the left is negative 9. 16≠-9
Step-by-step explanation:
The answer is (D) or 1728 In³
10 I think..I might be wrong
yez they can but it depend on wat type of triangle