Find the measure of the largest angle

One angle in a triangle has a measure that is three times as large as the smallest angle. The measure of the third angle is 40 degrees more than that of the smallest angle. Find the measure of the largest angle.

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x = smallest angle
3x = one angle {one angle is three times as large as smallest angle}
x + 40 = third angle {the third angle is 40 degrees more than the smallest angle}

​Angles of a triangle add up to 180 degrees.

x + 3x + x + 40 = 180 {added angles and set equal to 180}
5x + 40 = 180 {combined like terms}
5x = 140 {subtracted 40 from each side}
x = 28 {divided each side by 5}

The largest angle is 3x.
3x = 84 {substituted 28, in for x, into 3x}

84 degrees is the measure of the largest angle.

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