Answer:
Answer A
Step-by-step explanation:
We see that ABC is similar to DEF. Pay attention to the order of these letters. The order that they read (left-to-right) is the order that they are similar. For example, AB is similar to DE. Despite being different triangles, they are both the <em>first two </em>letters in the triangle. So, knowing this, we can conclude that answer choice A is correct.
Answer:

Step-by-step explanation:

add
to both sides

add
to both sides

divide both sides by 


Answer:
a= 3/5
decimal form: 0.6
Step-by-step explanation:
Answer:
D.
Step-by-step explanation:
The mean is 11,000
Answer:
-1/2
Step-by-step explanation:
Im not going to go into detail about how to compute sin30 and cos 30, but know that sine and cosine are just the ratios between the sides of a 30-60-90 triangle with a hypothenuse of 1.
With that being said:
sin^2 30 - cos^2 30
= (1/2)^2 - ((sqrt3)/2)^2
= 1/4 - 3/4
= -1/2