To find the measure of the third angle, we can use the Triangle Angle Sum Theorem, which states that the sum of the measures of the angles in a triangle is always 180 degrees.
Since angle A is 120 degrees and angle B is 34 degrees, we can add those two angles together to find the sum.
120 + 34 = 154 degrees.
To find the measure of the third angle, we subtract the sum from 180 degrees.
180 - 154 = 26 degrees.
Therefore, the measure of the third angle is 26 degrees.
Triangle Angle Sum Theorem Practice
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Question
Use the image to answer the question.
An illustration shows a triangle with vertices as A B C. Angle A on top is 120 degrees and angle B on the left is 34 degrees. Vertex C is on the right.
Use the Triangle Angle Sum Theorem to find the measure of the third angle of the triangle shown.
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