congruent triangles 61 videos

CPCTC
Geometry Triangles
How to use the principle that corresponding parts of congruent triangles are congruent, or CPCTC.
corresponding parts or congruent triangles proofs 
Midpoints and Congruent Segments
Geometry Geometry Building Blocks
How to identify, define and label a midpoint.
congruent segments bisect 
Area of Triangles
Geometry Area
How to derive the area of a triangle formula using the rectangle area formula.
area triangles rectangles altitude 
Types of Triangles
Geometry Geometry Building Blocks
How to classify a triangle based on its side lengths and angle measures.
equiangular equilateral isosceles right acute obtuse triangles 
Triangle Angle Sum
Geometry Triangles
How to apply the triangle angle sum theorem.
triangle angle sum theorem 180 degrees 
Similar Triangles in Circles and Right Triangles
Geometry Similarity
How to determine if two triangles in a circle are similar and how to prove that three similar triangles exist in a right triangle with an altitude.
similar inscribed angles intercepted arc right angle circle 
Using Sine to Calculate the Area of a Triangle
Geometry Basic Trigonometry
How to calculate the area of any triangle using two sides and an included angle.
area of a triangle sine 
Special Isosceles Triangle Properties
Geometry Triangles
How to identify a segment from the vertex angle in an isosceles triangle to the opposite side.
isosceles triangle angle bisector altitude median 
Triangle Midsegment Properties
Geometry Polygons
How to define a triangle midsegment and describe its special properties.
midsegment triangle parallel bases midpoint third side 
Corresponding Parts of Similar Triangles
Geometry Similarity
How to relate corresponding altitudes, medians and angle bisectors in similar triangles.
similar triangles altitude median angle bisector proportional 
306090 Triangles
Geometry Pythagorean Theorem
How to find the legs and hypotenuse in 306090 triangles when given: the short leg, the long leg, or the hypotenuse.
right triangle short leg long leg hypotenuse 
Constructing a Triangle Midsegment
Geometry Constructions
How to define a midsegment in a triangle.
midpoint segment median 
454590 Triangles
Geometry Pythagorean Theorem
How to find the length of a leg or hypotenuse in a 454590 triangle using the Pythagorean Theorem.
isosceles right triangle leg hypotenuse Pythagorean theorem square root 
Isosceles Triangles
Geometry Triangles
How to define isosceles triangles, their components and how to determine their properties.
vertex angle leg base base angle converse remote interior angles 
Triangle Side Inequalities
Geometry Triangles
How to determine the triangle side inequalities.
shortest distance side length inequalities 
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 
Triangle Side and Angle Inequalities
Geometry Triangles
How to determine the relationship between the side inequalities and angle inequalities in a triangle.
angles smallest to largest sides smallest to largest 
Equiangular Polygon Sums
Geometry Polygons
How to find the measure of one angle in any equiangular or regular polygon.
equiangular regular congruent triangles sum 
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 
HL
Geometry Triangles
How to use the hypotenuse leg shortcut to determine the congruence of right triangles.
hypotenuse leg triangle congruence right triangles