4.7 triangles and coordinate proof

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Transcript of 4.7 triangles and coordinate proof

Page 1: 4.7 triangles and coordinate proof

Triangles and Coordinate Proof

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Placing a rectangle in the coordinate plane

Place a 2-unit by 6-unit rectangle in the coordinate plane.

Solution Choose a placement that makes finding distances easy.

Two possible placements:

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Using the Distance Formula

• A right triangle has legs of 5 units and 12 units. Place the triangle in a coordinate plane. Label the coordinates of the vertices and find the length of the hypotenuse.

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Using the Midpoint Formula

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Writing Coordinate Proofs

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UTOV ||

OUOU ≅

Given, horizontal lines.

Definition of CongruenceOV = UT Transitive property of equality.

∠UOV ≅ ∠OUT Alternate Interior Angles Theorem

∆OTU ∆≅ UVO SAS Congruence Postulate

UTOV ≅

Reflexive property of congruence.

Writing Coordinate Proofs