Răspuns :
fie x masura unghiului
x=20(180grade-x)/100
x=(180grade-x)/5
5x=180grade-x
6x=180grade
x=30grade
verificare
masura suplement=150 grade
30 =150:5
30=30
adevarat, bine rezolvat
x=20(180grade-x)/100
x=(180grade-x)/5
5x=180grade-x
6x=180grade
x=30grade
verificare
masura suplement=150 grade
30 =150:5
30=30
adevarat, bine rezolvat