Finding m∠1 and Two Methods to Calculate the Missing Angle Measure of the Triangle

To find m∠1 in a triangle, you can use two different methods:

1. Sum of Angles in a Triangle: The sum of the interior angles in a triangle is always 180°. If you know the measures of the other two angles in the triangle, you can find m∠1 by subtracting the sum of the known angles from 180°. For example, if the other two angles are 60° and 70°, you would calculate m∠1 as follows:

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m∠1 = 180° – (60° + 70°) = 180° – 130° = 50°.

]

2. Using Exterior Angle Theorem: If you have an exterior angle that is adjacent to angle 1, you can find m∠1 by knowing that the exterior angle is equal to the sum of the two opposite interior angles. If, for example, the exterior angle is 110° and the opposite angle measures 30°, you would use:

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m∠1 = 110° – 30° = 80°.

]

Make sure to perform these calculations based on the values provided in the figure or problem!