Khan Academy
Khan Academy: Triangles: Bhaskara's Proof of Pythagorean Theorem
An elegant visual proof of the Pythagorean Theorem developed by the 12th century Indian mathematician Bhaskara.
Khan Academy
Khan Academy: Hexaflexagons: Hexaflexagons 2
This video is based on, and in honor of, Martin Gardner's column from 1956, "Hexaflexagons," which can be found here: http://maa.org/pubs/focus/Gardner_Hexaflexagons12_1956.pdf. For more information, see the top comment below.
Khan Academy
Khan Academy: Triangles: Another Pythagorean Theorem Proof
Students explore the Pythagorean Theorem by exploring a visual proof of the Theorem as they watch a video tutorial.
Khan Academy
Khan Academy: Hexaflexagons: Hexaflexagons
Watch a video to explore what a hexaflexagon is.
Sophia Learning
Sophia: Calculating the Area of a Triangle
Use different size triangle to determine how to solve for the area in this video lesson. Take quiz to check understanding. [3:41]
Sophia Learning
Sophia: Congruent Triangles
Take a look at two triangles and determine if the triangles are congruent in this video tutorial. [5:13] Check understanding with a quiz.
Sophia Learning
Sophia: Converse of the Pythagorean Theorem
Use the Pythagorean theorem to determine if the triangle is a right triangle. Assess learning with a quiz.
Sophia Learning
Sophia: Cpctc (Corresponding Parts of Congruent Triangles)
Complete a multiple step proof to determine if two triangles are congruent. Take quiz to check for understanding.
Sophia Learning
Sophia: Diagonal
In this video tutorial, the instructor defines and provides examples of diagonals in polygons. Students can check their understanding with an assessment. [3:21]
Sophia Learning
Sophia: Diagonals in Regular Polygons
In this video tutorial, the instructor demonstrates how to determine the number of diagonals in a regular polygon by looking at the number of vertices, and the number of diagonals. Use the formula to complete the assessment to check...
Sophia Learning
Sophia: Pythagorean Theorem Proof
Prove the Pythagorean theorem and take a quiz to assess learning.
Sophia Learning
Sophia: Quadrilateral
Quadrilateral is defined and examples are given in this video tutorial. [2:23] Check understanding with a quiz.
Sophia Learning
Sophia: Quadrilateral
In this video tutorial [4:00], define the term quadrilateral and what shapes are considered to be quadrilaterals. Take quiz to assess learning.
Sophia Learning
Sophia: Quadrilaterals and Triangles
This video lesson [4:55] describes the characteristics that quadrilaterals and triangles have in common. Students can check their understanding with an assessment.
Sophia Learning
Sophia: Regular Polygons Tutorial
In this video tutorial, students will determine if a polygon is regular by examining the sides and angles for congruency. Check understanding by the assessment. [2:06]
Sophia Learning
Sophia: Regular Polygons Tutorial
This video tutorial demonstrates how to use the terms equiangular and equilateral to determine if a polygon is regular or irregular. Check understanding with the assessment. [6:07]
Sophia Learning
Sophia: Square Practice Problems
This video demonstrates how to prove that a square is a square by solving for variables, side lengths, and angle measures. Assess learning with a quiz. [11:30]
Sophia Learning
Sophia: Tessellation
This video lesson introduces and provides examples of tessellations. Students can check their understanding with an assessment. [3:32]
Sophia Learning
Sophia: The Pythagorean Theorem
Determine how to find the missing side length or the hypotenuse of a right triangle using the Pythagorean theorem. Check understanding with a quiz.
Sophia Learning
Sophia: Area of a Parallelogram With Triangles and Rectangles
In this video tutorial lesson, determine the area of a parallelogram using triangles and rectangles then assess learning with a quiz. [3:34]
Sophia Learning
Sophia: Area of a Trapezoid
In this video, students will determine the area of a trapezoid and assess learning with a quiz. [4:24]
Sophia Learning
Sophia: Area of a Triangle
This video tutorial shares several examples of different types of triangles as they are used to determine the area of each triangle. Assessment checks understanding. [6:54]
Sophia Learning
Sophia: Area of Regular Polygons
This video lesson demonstrates how to find the area of any regular polygon using the apothem. Students can check their understanding with an assessment.