Question 462056
∠DEF and ∠ABC are supplementary, meaning they add up to 180°


x = ∠ABC
4x = ∠DEF {∠DEF is four times as large as ∠ABC}


x + 4x = 180 {supplementary angles add up to 180°}
5x = 180 {combined like terms}
x = 36 {divided both sides by 5}
4x = 144 {substituted 36, in for x, into 4x}


∠ABC = 36° and ∠DEF = 144°
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