Use different size triangle to determine how to solve for the area in this video lesson. Take quiz to check understanding. [3:41]
This video lesson demonstrates how to calculate the area of a triangle. It includes detailed examples including ones that use the Pythagorean Theorem. Students can check their understanding with an assessment. [10:43]
This task shows that the three perpendicular bisectors of the sides of a triangle all meet in a point, using the characterization of the perpendicular bisector of a line segment as the set of points equidistant from the two ends of the segment. The point so constructed is called the circumcenter of the triangle.
Discusses the different types of triangles and their angles. [6:00]
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This video lesson describes and provides examples of right, acute, and obtuse triangles. Students can check their understanding with an assessment. [2:24]
This video lesson shows examples of classifying triangles by their angle measurements. Students can check their understanding with an assessment. [3:54]
Explains how to classify a triangle just by knowing the angle sizes. [5:30]
Khan Academy learning modules include a Community space where users can ask questions and seek help from community members. Educators should consult with their Technology administrators to determine the use of Khan Academy learning modules in their classroom. Please review materials from external sites before sharing with students.
This interactive exercise focuses on the appearance and manipulation of triangles.
This lesson [2:00] will define the phrase corresponding parts (e.g. angles, sides, etc.). It is 1 of 5 in the series titled "Corresponding Parts."
This lesson [4:27] will define the phrase corresponding parts (e.g. angles, sides, etc.). It is 2 of 5 in the series titled "Corresponding Parts."
This video segment adapted from the PBS series "Building Big" shows how a structural engineer overcame the challenges of building New York's Citigroup skyscraper over a church by using triangles to add muscle and stability to the structure. [4:26]
Congruent triangles are investigated in this video lesson. The tutorial demonstrates how to use four tricks to determine if triangles are congruent. Students can check their understanding with an assessment. [5:27]
This video tutorial describes four ways to determine if two triangles are congruent. Students can check their understanding with an assessment. [5:40]
Students watch a video and attempt practice problems on classifying rectangles, squares, circles and triangles.
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Students practice classifying various two dimensional shapes as rectangles, squares, circles or triangles.
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Students watch a video overview and attempt practice problems on classifying triangles based on length of sides.
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Students watch a video overview on how to classify triangles based on side length.
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Students watch a video overview and attempt practice problems on classifying triangles based on the number of equal sides.
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Students watch a video and attempt practice problems on finding the missing angles in triangles.
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Students watch a video tutorial and attempt practice problems on how to determine the unknown side length of a triangle.
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