Question 714752
as a=4b so b=a/4
so,

4•a/4+a/4+2a-15=180 

4•a/4+a/4+2a-15-180=0 

5•a/4+2a-195=0 
(5a)/4+(2a-195)=0 
((5a)+4(2a-195))/4=0 

Now we remove the brackets.
(5a+8a-780)4=0
 
Arrange the terms.
(13a-780)4=0 
Let common 13 from the value
(13(a-60))/4=0 
(13/4)*(a-60)=0

a-60=0 
Let's move the constants to the right-hand side of the equality with the reverse sign.
a=60 
The final answer is: a=60 


the first angle is =a =60
the second angle is =b =a/4=15
the third angle is = c = 2a -15 = 2(60) -15=120 -15=105