pag.192:
unghiurile exterioare au masurile : 80 gr., 70 gr., 30 gr
(360 - 150 ×2) /2 = 30
(360 - 110 ×2) / 2 = 70
(360 -100 ×2 )/ 2 = 80
10. b)
40 +2x +5 +x =180
3x=135
x=45
mas.ungh.A=2x+5=90+5 =95 gr
mas.ungh.C=45
c)
70 +4x+12+5x -10 =180
9x =108
x=12
mas.ungh.A=4x+12=48+12=60 gr
mas.ungh.C=5x-10=50