GEOMETRYHELP

The angles with labeled measures are vertical angles because their sides are opposite rays. Apply the Vertical Angles Theorem to find x.

Find the value of x.

4x – 101 = 2x + 3 Vertical Angles Theorem

4x = 2x + 104 Addition Property of Equality

2x = 104 Subtraction Property of Equality

x = 52 Division Property of Equality

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Proving Angles CongruentLESSON 2-5

Additional Examples

GEOMETRYHELP

Write a paragraph proof using the given, what you

are to prove, and the diagram.

Given: WX = YZ

Prove: WY = XZ

Proof: It is given that WX = YZ. Adding the middle segment, XY, to each

smaller segment gives WX + XY = YZ + XY.

Using substitution, you get WY = XZ.

By the Segment Addition Postulate, WX + XY = WY, and XY + YZ = XZ.

Proving Angles CongruentLESSON 2-5

Additional Examples

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