1: 9 1/3
2: 12 1/2
3: 14 3/4
Step-by-step explanation:
A=BH
H=A/B
B=A/H
B = Base
H = Height 
A = Area
Hope this help!
 
        
             
        
        
        
b) ( 7, 21)
Step-by-step explanation:
5(7)=2(21)-7
35=42-7
35=35
 
        
                    
             
        
        
        
We don't know what the answer choices are!!
 
        
             
        
        
        
Find the inside angle B of the smaller triangle using the base (4) and height (6)
smaller part of B =  arctan(4/6) = 33.69 degrees
 full B = 90 degrees - smaller B gives you the other part of B for the left hand side
so 90 - 33.69 = 56.31
now AD =  6 x tan(56.31) = 9 feet
 answer is G