Since it's isosceles, ∠ABC = (180-30) / 2 = 75
        
                    
             
        
        
        
The answer is 21 + 4x.
You find this answer by adding up all the sides.
9+12+4x= 21+4x ... you don't add 4x because it has a variable that we do not know of the value.
        
             
        
        
        
Answer:
Step-by-step explanation:
 
        
             
        
        
        
Answer:
Height of second tower = 17.32m
Step-by-step explanation:
I have attached a diagram depicting the question. 
From the diagram, The first tower is depicted by side AEB and the second tower CD. 
While d is the distance that separates the two towers and it's given as 15m.
Now, since the angle of depression of the second tower’s base is 60°, then for triangle BAC. Angle C = 60°.
Thus; using trigonometric ratios;
tan 60° = AB/AC.
This gives; AB = d*tan 60°
Similarly, for the triangle BED, BE = d*tan 30°
Since, AE = CD, thus ;
CD = AB − BE
CD = d (tan 60° − tan 30°)
CD = 15(1.7321 − 0.5774) 
CD = 15 × 1.1547
CD ≈ 17.32 m.
So, height of second tower = 17.32 m
 
        
             
        
        
        
Answer:
1.1 
Step-by-step explanation:
I think it.