Răspuns :
Răspuns:
A+B+C= 180°
A+2A+15+A/2+60=180
3A+A/2=180-60-15
3A+A/2=105 |×2
6A+A=210
7A=210
A=210/7
A=30
B=2A+15=75
C=A/2+60=15+60=75
B=C=75=> ABC triunghi isoscel
Răspuns:
Explicație pas cu pas:
B=2A+15
C=A/2+60
A+B+C=180 A+2A+15+A/2+60=180 3A+A/2=180-60-15
7A/2=105 7A=2×7×15 ⇒∡A=30°
∡B=2×30+ 15=60+15=75°
∡C=∡A/2+60=15+60=75°
⇒∡B=∡C=75°⇒ ΔABC este Δ isoscel