Two Column Proofs - Proving Isosceles Trapezoids - Geometry

This geometry video tutorial explains how to use two column proofs to do prove if a figure is indeed an isosceles trapezoid. Theorems used in this video include the vertical angle theorem, the AAS triangle congruence postulate, CPCTC, and the reflexive property.

Polygons:

Angles of Regular Polygons:

Quadrilaterals:

Parallelograms:

Rectangles - Special Quadrilaterals:

Isosceles Trapezoids:

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The Rhombus:

Kites:

Proving Parallelograms:

Proving a Quadrilateral Is a Kite:

Proving a Quadrilateral Is a Rhombus:

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2 Column Proofs - Quadrilateral:

Skew Lines:

Points, Lines, Planes, & Segments:

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Final Exams and Video Playlists:

Full-Length Videos and Worksheets:

[georgesadler]

MR. Organic Chemistry Tutor, thank you once again for another monster video/lecture on Proving Isosceles Trapezoids in Solid Geometry. From analyzing the two columns' proofs, I am getting a better read on how proofs are done in Geometry. Proofs are the real deal in higher level Mathematics.

[Rv_pilot]

I love how I find this after I fail my midterm.

[TaiTriH]

Dear, For the example one, I think you need show one more line that BD == AC before the conclusion. Because you didn't give BC // AD
And for the example two, should have add AB == CD with BD == AC.