A) Perimeter of Trapezium = 8+5+6+15.5
 = 34.5in 
 Area= 1/2*(a+b)*h
 =1/2*(8+15.5)*4
 =47in^2
B)Perimeter= 12+6+8.5
 =26.5mm
 Area=1/2*b*h 
 =1/2*12*4
 =24mm^2
        
             
        
        
        
Answer:
option-C
Step-by-step explanation:
We are given 
At 9:00 a.m., a wind speed of 20 miles per hour was recorded
So, initial wind speed =20 miles per hour
Each measurement showed an increase in wind speed of 3 miles per hour
The strongest wind was recorded at 4:00 p.m
so, 
top wind speed = initial wind speed + ( total number of hours between 9:00 am and  4:00 pm)*(change in wind speed)
top wind speed = 20 mph+(16-9)*3

 miles per hour
 miles per hour
Since, change in wind speed and initial wind speed are constant 
but the number of hours it took for the wind speed to reach its minimum for the day can be changed
so, most important variables is 
the number of hours it took for the wind speed to reach its minimum for the day can be changed