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Pearson Geometry Common Core, 2011

PG

Pearson Geometry Common Core, 2011 View details

6. Proving Angles Congruent

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Exercise 36 Page 127

If angles are vertical, then they are congruent.

x=18

Practice makes perfect

To determine x, we should first recognize that the given angles are vertical angles. This means that they are congruent by the Vertical Angles Theorem.

From the exercise we know that m∠1=63 and m∠2=4x-9. We can equate the expressions for the two angle measures and solve for x.

63=4x-9

▼

Solve for x

LHS+9=RHS+9

72=4x

.LHS /4.=.RHS /4.

18=x

Rearrange equation

x=18

Subchapter links

Lesson Check p.124

Standardized Test Prep p.127

Mixed Review p.127