Find missing angles in triangles
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The sum of the measures of the angles of a triangle is 180º.
A+B+C=180º
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Find the measure of the missing angle
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Since the sum of the angle measures in a quadrilateral is 180º, x+120+30=180
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x + 120 + 30
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180 |
Write the equation
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x + 150
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180 |
Add 120, and 30
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x+150-150
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= |
180-150 |
Subtract 150 from each side
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x
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= |
30 |
Simplify
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So, the value of x is 30º.
