Answer: x = -4 ; Angle = 60°
Concept:
The given figure is a triangle with 3 arc signs on each angle. This <u>arc sign </u>stands for the corresponding angles are congruent, which in this question, it shows that all three angles are congruent. Sometimes, if the figure has multiple angles and there are different groupings of congruent angles, then we use different numbers of arcs or symbols.
Solve:
<u>Given information</u>
An angle = 3x + 72
Total measure of angles = 180 (triangle angle sum theorem)
Total number of congruent angles = 3
<u>Given expression</u>
Total measure = Total number of congruent angles × An angle measure
<u>Substitute values into the expression</u>
180 = 3 (3x + 72)
<u>Divide 3 on both sides</u>
180 / 3 = 3 (3x + 72) / 3
60 = 3x + 72
<u>Subtract 72 on both sides</u>
60 - 72 = 3x + 72 - 72
-12 = 3x
<u>Divide 3 on both sides</u>
-12 / 3 = 3x / 3
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<u>Find the angle measure</u>
3x + 72 = 3 (-4) + 72 =
Hope this helps!! :)
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