In an isosceles triangle, the base angles are congruent. The third angle is called the vertex angle.
Here, the vertex angle is <A.
Therefore, m<C = m<B.
m<A = 3m<B + 20
m<A + m<B + m<C = 180
3m<B + 20 + m<B + m<B = 180
5m<B + 20 = 180
5m<B = 160
m<B = 32
m<C = m<B = 32
Answer: m<C = 32 deg
 
        
             
        
        
        
It decreased by twenty five precent 25%
        
                    
             
        
        
        
The general form of an equation is 

. Solving for  (5+X)(5-X)=7 by multiplying the factors and subtratcting 7 on both sides gives the equation 

, so 
A = 1
B = 0
C = -18
 
        
        
        
Answer: Complementary angles
Step-by-step explanation:
wxy is making a 90 degree angle which is a complementary. A supplementary is a 180 degree angle