1. Intersection
2. complement
3. Union
4. finite set
5. disjoint sets
6. proper subset
7. subset
r-12
substitute in r=7
so 7-12 = -5
We know that the trigonometric identity that uses the adjacent side and the hypotenuse is cosine. We can set this up as:

We need to solve for x, so let's isolate it:

So,
x = 10.2 units
Answer:
36
Step-by-step explanation:
Think of the unknown sized side as a half of 12 and multiply them together when your triangle is obtuse like that. and split the answer from 6 times 12.
I hope this helped you!
Answer:
Reflexive property
Step-by-step explanation:
The property means that a real number is always equal to itself. For example, x=x. It works for all real numbers and is pretty simple. 3=3, 7.5=7.5 and etc