Question 1113589
If AB = BC, triangle ABC is isosceles,
with congruent angles at A and C,
meaning that those angles have the same measure.
If the measures of those angles, in degrees, are {{{8x}}} and {{{3x+50}}} .
then {{{8x=3x+50}}} .
 
Solving that equation:
{{{8x=3x+50}}}
{{{8x-3x=3x+50-3x}}}
{{{5x=50}}}
{{{x=10}}} .
 
So the measure of angle A, in degrees, is
{{{8x=8*10-80}}} .
Angle A measures {{{highlight(80^o)}}} .
Angle C has the same measure,
and angle B measures
{{{180^o-2(80^o)=180^o-160^o=20^o}}} .
{{{drawing(100,300,-1.1,1.1,-0.4,6.2,
triangle(-1,0,1,0,0,5.671),
locate(-1.05,0,A),locate(0.95,0,C),
locate(-0.05,6,B)
)}}}