Question 177443
lets call our angles a,b,and c
:
we are given that 
:
a=4b.......eq 1
c=7b.......eq 2
: we know by rule that:
a+b+c=180..eq 3
:
lets plug a's value from eq 1 and c's value from eq 2 into eq 3
:
4b+b+7b=180
:
12b=180
:
{{{highlight(b=15)}}}degrees
:
{{{a=4b=4(15)=highlight(60)}}}degrees
:
{{{c=7b=7(15)=highlight(105)}}}degrees