Curated OER
English Vocabulary Skills: AWL Sublist 4 - Exercise 4b
In this online interactive English vocabulary skills activity, students answer 10 matching questions which require them to fill in the blanks in 10 sentences. Students may submit their answers to be scored.
Curated OER
Chalkboard Challenge: Fifth Grade Math Review
This PowerPoint addresses fifth grade math concepts, focusing mostly on geometry. The interactive math review game is in a "Jeopardy" style format and enables students to revisit the topics in geometry such as polygons, quadrilaterals...
Curated OER
4th Grade Math Worksheet
In this 4th grade math review worksheet, students respond to 60 multiple choice questions that review of fractions, decimals, geometry, number sense, and computation.
Curated OER
Polygons All Around Us!
Pupils explore the concept of polygon properties. In this polygon properties lesson, students draw polygons with different numbers of sides such as pentagons, octagons, hexagons, etc. Pupils identify different geometric shapes in the...
Texas Instruments
Texas Instruments: Angle Sum in Triangles Proof: Rotation and a Parallel Line
This investigation uses Cabri Jr. and a cleaver rotation of a triangle to "prove" that the angles in a triangle add up to 180. This could be used to reinforce triangles and paralled lines as well as introduce the concept of rotating an...
Illustrative Mathematics
Illustrative Mathematics: 8.g.a Triangle's Interior Angles
In this task, 8th graders are presented with a drawing of two parallel lines with a triangle touching them at all three of its vertices. They are asked to prove that the sum of the triangles' angles equals 180 degrees. Aligns with 8.G.A.5.
Khan Academy
Khan Academy: Triangle Angles Review
Reviews the rule that the interior angles of a triangle always add up to 180 degrees. Includes three practice problems.
CK-12 Foundation
Ck 12: Elem Math: Determining the Unknown Angle in a Triangle
[Free Registration/Login may be required to access all resource tools.] Students watch a video and attempt practice problems on how to determine a missing angle in a triangle.
Illustrative Mathematics
Illustrative Mathematics: A ced.a.1: Sum of Angles in a Polygon
This problem provides students with an opportunity to discover algebraic structure in a geometric context. They will divide up polygons into triangles. The will use the sum of the angles of 180 degrees for each triangle. Aligns with...
CK-12 Foundation
Ck 12: Geometry: Triangle Sum Theorem Grade 7
[Free Registration/Login may be required to access all resource tools.] Recognize the sum of the interior angles of a triangle as 180 degrees.
CK-12 Foundation
Ck 12: Geometry: Triangle Sum Theorem Grades 8 10
[Free Registration/Login may be required to access all resource tools.] Recognize the sum of the interior angles of a triangle as 180 degrees.
Texas Instruments
Texas Instruments: Extension: Parallel Lines and the Sum of the Angles
Students construct a line parallel to the base of a triangle and measure the angles formed. They use the construction to prove that the sum of the measures of the interior angles of a triangle is 180 degrees.
Math Is Fun
Math Is Fun: Triangles Contain 180 Degrees
Students learn about the angle-sum theorem. A definition, example, and proof are included.
Mangahigh
Mangahigh: Shape: Proof of the Sum of the Angles in a Triangle
Determine that all angles in a triangle equal 180 degrees.
Walter Fendt
Walter Fendt: Sum of Angles in a Triangle
A short interactive activity to show that the sum of the angles of a triangle is 180 degrees.