Question 712592
x = angle a
2x = angle b {angle b is twice angle a}
x + 20 = angle c {angle c is 20 more than angle a}


x + 2x + x + 20 = 180 {angles of a triangle add up to 180}
4x + 20 = 180 {combined like terms}
4x = 160 {subtracted 20 from each side}
x = 40 {divided each side by 4}
2x = 80 {substituted 40, in for x, into 2x}
x + 20 = 60 {substituted 40, in for x, into x + 20}


40°, 60°, and 80° are the three angles
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