Answer:
I'm not sure about "11" but  12. is "by the definition of right angles", and 16. is "by the SAS(side angle side) congruency theorem"
 
        
             
        
        
        
Answer:

Step-by-step explanation:
we know that
The perimeter of quadrilateral PQRS is equal to the sum of its four length sides
the formula to calculate the distance between two points is equal to

we have
the vertices P(2,4), Q(2,3), R(-2,-2), and S(-2,3)
step 1
Find the distance PQ
 P(2,4), Q(2,3)
substitute in the formula




step 2
Find the distance QR
 Q(2,3), R(-2,-2)
substitute in the formula



step 3
Find the distance RS
R(-2,-2), and S(-2,3)
substitute in the formula



step 4
Find the distance PS
 P(2,4), S(-2,3)
substitute in the formula



step 5
Find the perimeter

substitute the values



 
        
             
        
        
        
Answer:
20
Step-by-step explanation:
the number line is patterned in twos, so the dot will be at 20, since its 4 spaces away from 12
 
        
                    
             
        
        
        
Step-by-step explanation: 
22x13, 10x9, then both answers from the previous equations multiplied. Any questions?