The degree of the second angle of a triangle is four times that of the first angle, while the degree of the third angle is 5 / 2 more than the sum of the degrees of the first and second angles. How many are the three angles

The degree of the second angle of a triangle is four times that of the first angle, while the degree of the third angle is 5 / 2 more than the sum of the degrees of the first and second angles. How many are the three angles

∠2=4∠1∠3=(∠1+∠2)(1+2/5)∠1+∠2+∠3=180∠1+∠2=180-∠3∠3=(∠1+∠2)(1+2/5)∠3=7/5(180-∠3)12/5∠3=180∠3=75∠1+∠2=180-∠3=180-75=105∠1+4∠1=105∠1=21∠2=105-21=84∠1=21∠2=84∠3=75...