congruent 19 videos

Midpoints and Congruent Segments
Geometry Geometry Building Blocks
How to identify, define and label a midpoint.
congruent segments bisect 
CPCTC
Geometry Triangles
How to use the principle that corresponding parts of congruent triangles are congruent, or CPCTC.
corresponding parts or congruent triangles proofs 
Angle Bisectors
Geometry Geometry Building Blocks
How to label an angle bisector; how to use an angle bisector to find a missing variable.
congruent angles ray 
Vertical Angles
Geometry Reasoning, Diagonals, Angles and Parallel Lines
How to define and identify vertical angles.
vertex intersecting lines congruent 
Why SSA and AAA Don't Work as Congruence Shortcuts
Geometry Triangles
How to determine which congruence shortcuts do not work and why.
congruent triangles shortcuts 
Central Angles and Intercepted Arcs
Geometry Circles
How to define a central angle and find the measure of its intercepted arc; how to describe the intercepted arcs of congruent chords.
chord central angle intercepted arc arc measure congruent chords side side side shortcut 
Similar Triangles
PreAlgebra Introductory Geometry
Overview of similarity: congruent angles, proportional corresponding sides

Cyclic Quadrilaterals and Parallel Lines in Circles
Geometry Circles
How to prove that opposite angles in a cyclic quadrilateral are congruent; how to prove that parallel lines create congruent arcs in a circle.
inscribed angles cyclic quadrilaterals parallel lines alternate interior angles 
Duplicating a Line Segment
Geometry Constructions
How to duplicate a line segment using a compass and straightedge.
congruent segments construction compass straightedge 
Duplicating an Angle
Geometry Constructions
How to duplicate an angle using a compass and straightedge.
congruent angles construction compass straightedge 
Equiangular Polygon Sums
Geometry Polygons
How to find the measure of one angle in any equiangular or regular polygon.
equiangular regular congruent triangles sum 
Tangent Segments to a Circle
Geometry Circles
How to find the length of tangent segments drawn to a circle from the same point.
tangent congruent segments inscribed circle 
Two Column Proofs
Geometry Triangles
How to organize a two column proof.
statement reason cpctc prove show congruent triangles 
Rhombus Properties
Geometry Polygons
How to define a rhombus and compare it to a square and rectangle.
rhombus congruent sides parallelogram angle bisectors perpendicular bisectors rectangles diagonals 
Rectangle and Square Properties
Geometry Polygons
How to define a rectangle and a square.
equiangular polygon congruent diagonals bisect regular quadrilateral angle bisectors 
Chords and a Circle's Center
Geometry Circles
How to define a chord; how to describe the effect of a perpendicular bisector of a chord and the distance from the center of the circle.
chord perpendicular bisector distance from the center congruent chords 
Inscribed Angles
Geometry Circles
How to calculate the measure of an inscribed angle.
inscribed angle intercepted arc central angle congruent arcs 
Center and Apothem of Regular Polygons
Geometry Area
How to define the apothem and center of a polygon; how to divide a regular polygon into congruent triangles.
center circumscribed circle inscribed polygon isosceles triangle regular hexagon 
Parts of a Circle
Geometry Geometry Building Blocks
How to define a circle and identify its main parts.
center chord diameter radius congruent circles concentric circles arc minor arc major arc semicircle central angle