Question

construct a triangle klm if its perimeter is 10.5 .angle l is 120degre and angle m is 30 degri

Answer 1

first draw a line of 10.5 cm n say it as AB 
then at A construct the angle 120 with the help of compass 
and on B construct an angle 30 degree with the help of compass 
now bisect the angle A and angle B 
now join the lines of bisector of these angles at k 
now bisect the line AK and BK  and thier bisectors will meet the line AB at l and m 
join KLM and required triangle is formed