ISEE Upper Level Math : How to find an angle in a parallelogram

Study concepts, example questions & explanations for ISEE Upper Level Math

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Example Questions

Example Question #52 : Quadrilaterals

Solve for \displaystyle x:

Problem_10

Possible Answers:

\displaystyle x=95

\displaystyle x=19

\displaystyle x=89

\displaystyle x=109

Correct answer:

\displaystyle x=109

Explanation:

Find the sum of the interior angles of the polygon using the following equation where n is equal to the number of sides.

\displaystyle =180(n-2)

\displaystyle 180(4-2)=180(2)=360

The sum of the angles must equal 360.

\displaystyle 360=x+71+x+71=2x+142

\displaystyle 360-142=2x+142-142

\displaystyle 218=2x

\displaystyle 109=x

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