length 13 videos

Arc Length
Geometry Circles
How to define arc length and how it is different from arc measure; how to calculate the length of an arc.
arc length arc measure concentric circles fraction circumference radius diameter 
Triangle Side Inequalities
Geometry Triangles
How to determine the triangle side inequalities.
shortest distance side length inequalities 
Trapezoid Midsegment Properties
Geometry Polygons
How to define the midsegment of a trapezoid, calculate its length, and relate it to a triangle midsegment.
midsegment trapezoid average bases midpoint 
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 
Secants
Geometry Circles
How to define a secant; how to find the length of various secants in circles.
secant intercepted arcs proportion arc measure tangent chord 
Angle Bisectors and Opposite Side Ratios
Geometry Similarity
How to relate the sides of an angle bisected and the lengths of the opposite side.
angle bisector opposite side ratio proportion 
Similarity and Area Ratios
Geometry Similarity
How to convert between length and area ratios of similar polygons
polygons similar area ratios 
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 
Area of Kites and Rhombuses
Geometry Area
How to derive the area formula of a kite based on the rectangle formula; how to calculate the area of a rectangle using diagonal lengths.
kite area diagonals consecutive sides vertex angle non vertex angle bisect perpendicular rhombus 
Using the Pythagorean Theorem to find a Missing Hypotenuse
Geometry Pythagorean Theorem
How to calculate the hypotenuse in a right triangle given the lengths of the legs using the Pythagorean Theorem.
Pythagorean theorem leg hypotenuse right triangle 
Using the Pythagorean Theorem to find a Missing Leg
Geometry Pythagorean Theorem
How to use the Pythagorean Theorem to find a missing leg, given the length of the hypotenuse and a leg.
Pythagorean theorem leg hypotenuse right triangle 
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 
Converse of the Pythagorean Theorem
Geometry Pythagorean Theorem
How to use the converse of the Pythagorean Theorem to determine if a triangle is a right triangle, how to use Pythagorean triples to memorize the lengths of certain right triangles.
right triangle leg hypotenuse converse Pythagorean triples