Yes, i<span>n mathematics, a </span>rational number<span> is any </span>number<span>that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q.</span>
        
                    
             
        
        
        
Answer:
30m
Step-by-step explanation:
A=πr²
225π=πr²
225=r²
r=√225
r=15
d=2r
d=2×15
=30m
 
        
             
        
        
        
Answer:
Option C. 
Step-by-step explanation:
we know that
The volume of a cylinder is equal to

we have


substitute


 
        
                    
             
        
        
        
Question is Incomplete, Complete question is given below.
Prove that a triangle with the sides (a − 1) cm, 2√a cm and (a + 1) cm is a right angled triangle.
Answer:
∆ABC is right angled triangle with right angle at B.
Step-by-step explanation:
Given : Triangle having sides (a - 1) cm, 2√a and (a + 1) cm.  
We need to prove that triangle is the right angled triangle.
Let the triangle be denoted by Δ ABC with side as;
AB = (a - 1) cm 
BC = (2√ a) cm
CA = (a + 1) cm  
Hence, 
 
 
Now We know that

So;


Now;

Also;

Now We know that




[By Pythagoras theorem]

Hence, 
Now In right angled triangle the sum of square of two sides of triangle is equal to square of the third side.
This proves that ∆ABC is right angled triangle with right angle at B.
 
        
             
        
        
        
Answer:
14.99
Step-by-step explanation: