A:b= 5:8 and b:c=6:25
Find, in its simplest form, the ratio a:b:c

a:b:c = 15:24:100.

Step-by-step explanation:

We need to make the values of b the same in both ratios so we multiply b = 6 by 4/3 to make it 8 and also multiply 25 by 4/3.

6  25 = 8 : 33.33

So a:b:c = 5:8:33.33...

To convert to whole numbers we multiply by 3:

a:b:c = 15:24:100.

Yes, your proof is correct;

However, you should supply the REASONS

angle 2 + angle 3 + angle 4 = 180 < GIVEN

angle 1 + angle 2 = 180 <--- given

angle 1 + angle 2 = angle 2 + angle 3 + angle 4  <--- substitution/ transitive

angle1 + angle 2 - angle 2 = angle 2 + angle 3 + angle 4 - angle 2 <--- subtracts angle 2 from both side

angle 1 = angle 3 + angle 4