Answer:
Because they are equal (Right angle)
Two figures or objects are congruent if they have the same shape and size, or if one has the same shape and size as the mirror image of the other.
Answer:
The result is 19
Step-by-step explanation:

Step 1: Parenthesizing (5-2)=3

Step 2: Exponentiation 

Step 3: Multiplication and division 3x4=12 and 6/3=2

Step 4: Addition and subtraction 9+12=21, and 21-2=19
21-2
19
The operations are ordered from highest to lowest in the order:
1. Parenthesizing,
2. Factorial,
3. Exponentiation,
4. Multiplication and division,
5. Addition and subtraction.
Hope this helps!
Answer:
Linear. While all linear equations produce straight lines when graphed, not all linear equations produce linear functions. In order to be a linear function, a graph must be both linear (a straight line) and a function (matching each x-value to only one y-value).