Answer:
m∠A = 18
Step-by-step explanation:
Formula:
the sum of the interior angles of a triangle is 180.
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According to the formula :
[tex]m\angle A\ +\ m\angle B\ +\ m\angle C=180[/tex]
⇔ x - 22 + 3x + 19 + x - 17 = 180
⇔ 5x + (19 - 17 - 22) = 180
⇔ 5x + (2 - 22) = 180
⇔ 5x - 20 = 180
⇔ 5x = 180 + 20
⇔ 5x = 200
[tex]\Leftrightarrow x = \frac{200}{5} \\\Leftrightarrow x = 40[/tex]
Conclusion:
m∠A = x - 22 = 40 - 22 = 18
